Search criteria
ⓘ
Use this form to refine search results.
Full-text search supports keyword queries with ranking and filtering.
You can combine vendor, product, and sources to narrow results.
Enable “Apply ordering” to sort by date instead of relevance.
786 vulnerabilities found for mattermost_server by mattermost
CVE-2026-3590 (GCVE-0-2026-3590)
Vulnerability from nvd – Published: 2026-04-15 11:00 – Updated: 2026-04-15 14:00
VLAI?
Title
Race Condition in Guest Magic Link Authentication Allows Token Reuse
Summary
Mattermost versions 10.11.x <= 10.11.12, 11.5.x <= 11.5.0, 11.4.x <= 11.4.2, 11.3.x <= 11.3.2 fail to enforce atomic single-use consumption of guest magic link tokens, which allows an attacker with access to a valid magic link to establish multiple independent authenticated sessions via concurrent requests.. Mattermost Advisory ID: MMSA-2026-00624
Severity ?
6.5 (Medium)
CWE
- CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
10.11.0 , ≤ 10.11.12
(semver)
Affected: 11.5.0 , ≤ 11.5.0 (semver) Affected: 11.4.0 , ≤ 11.4.2 (semver) Affected: 11.3.0 , ≤ 11.3.2 (semver) Unaffected: 11.6.0 Unaffected: 10.11.13 Unaffected: 11.5.1 Unaffected: 11.4.3 Unaffected: 11.3.3 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-3590",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-15T14:00:15.919479Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-15T14:00:27.030Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "10.11.12",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.5.0",
"status": "affected",
"version": "11.5.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.4.2",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.2",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.6.0"
},
{
"status": "unaffected",
"version": "10.11.13"
},
{
"status": "unaffected",
"version": "11.5.1"
},
{
"status": "unaffected",
"version": "11.4.3"
},
{
"status": "unaffected",
"version": "11.3.3"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Edgar Bellot Mic\u00f3"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 10.11.x \u003c= 10.11.12, 11.5.x \u003c= 11.5.0, 11.4.x \u003c= 11.4.2, 11.3.x \u003c= 11.3.2 fail to enforce atomic single-use consumption of guest magic link tokens, which allows an attacker with access to a valid magic link to establish multiple independent authenticated sessions via concurrent requests.. Mattermost Advisory ID: MMSA-2026-00624"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 6.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-367",
"description": "CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-15T11:00:14.880Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00624",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.6.0, 10.11.13, 11.5.1, 11.4.3, 11.3.3 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00624",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67791"
],
"discovery": "EXTERNAL"
},
"title": "Race Condition in Guest Magic Link Authentication Allows Token Reuse",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-3590",
"datePublished": "2026-04-15T11:00:14.880Z",
"dateReserved": "2026-03-05T11:34:57.712Z",
"dateUpdated": "2026-04-15T14:00:27.030Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-28741 (GCVE-0-2026-28741)
Vulnerability from nvd – Published: 2026-04-15 10:13 – Updated: 2026-04-15 15:39
VLAI?
Title
CSRF Protection Bypass Allows Updating a User's Authentication Method
Summary
Mattermost versions 10.11.x <= 10.11.12, 11.5.x <= 11.5.0, 11.4.x <= 11.4.2, 11.3.x <= 11.3.2 fail to validate CSRF tokens on an authentication endpoint which allows an attacker to update a user's authentication method via a CSRF attack by tricking a user into visiting a malicious page. Mattermost Advisory ID: MMSA-2026-00625
Severity ?
6.8 (Medium)
CWE
- CWE-352 - Cross-Site Request Forgery (CSRF)
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
10.11.0 , ≤ 10.11.12
(semver)
Affected: 11.5.0 , ≤ 11.5.0 (semver) Affected: 11.4.0 , ≤ 11.4.2 (semver) Affected: 11.3.0 , ≤ 11.3.2 (semver) Unaffected: 10.11.13 Unaffected: 11.5.1 Unaffected: 11.4.3 Unaffected: 11.3.3 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-28741",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-15T15:39:07.449816Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-15T15:39:52.265Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "10.11.12",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.5.0",
"status": "affected",
"version": "11.5.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.4.2",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.2",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "10.11.13"
},
{
"status": "unaffected",
"version": "11.5.1"
},
{
"status": "unaffected",
"version": "11.4.3"
},
{
"status": "unaffected",
"version": "11.3.3"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Eva Sarafianou"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 10.11.x \u003c= 10.11.12, 11.5.x \u003c= 11.5.0, 11.4.x \u003c= 11.4.2, 11.3.x \u003c= 11.3.2 fail to validate CSRF tokens on an authentication endpoint which allows an attacker to update a user\u0027s authentication method via a CSRF attack by tricking a user into visiting a malicious page. Mattermost Advisory ID: MMSA-2026-00625"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "HIGH",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 6.8,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-352",
"description": "CWE-352: Cross-Site Request Forgery (CSRF)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-15T10:13:33.950Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00625",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 10.11.13, 11.5.1, 11.4.3, 11.3.3 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00625",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67789"
],
"discovery": "EXTERNAL"
},
"title": "CSRF Protection Bypass Allows Updating a User\u0027s Authentication Method",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-28741",
"datePublished": "2026-04-15T10:13:33.950Z",
"dateReserved": "2026-03-10T13:45:39.984Z",
"dateUpdated": "2026-04-15T15:39:52.265Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-27769 (GCVE-0-2026-27769)
Vulnerability from nvd – Published: 2026-04-15 10:11 – Updated: 2026-04-15 13:08
VLAI?
Title
Connected Workspaces: Malicious remote server can manipulate arbitrary user's status
Summary
Mattermost versions 10.11.x <= 10.11.12 fail to validate whether users were correctly owned by the correct Connected Workspace which allows a malicious remote server connected using the Conntexted Workspaces feature to change the displayed status of local users via the Connected Workspaces API.. Mattermost Advisory ID: MMSA-2026-00603
Severity ?
CWE
- CWE-862 - Missing Authorization
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
10.11.0 , ≤ 10.11.12
(semver)
Unaffected: 11.5.0 Unaffected: 10.11.13 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-27769",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-15T13:08:29.628271Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-15T13:08:35.452Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "10.11.12",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "10.11.13"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "daw10"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 10.11.x \u003c= 10.11.12 fail to validate whether users were correctly owned by the correct Connected Workspace which allows a malicious remote server connected using the Conntexted Workspaces feature to change the displayed status of local users via the Connected Workspaces API.. Mattermost Advisory ID: MMSA-2026-00603"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 2.7,
"baseSeverity": "LOW",
"confidentialityImpact": "NONE",
"integrityImpact": "LOW",
"privilegesRequired": "HIGH",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "CWE-862: Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-15T10:11:07.676Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00603",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 10.11.13 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00603",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67521"
],
"discovery": "EXTERNAL"
},
"title": "Connected Workspaces: Malicious remote server can manipulate arbitrary user\u0027s status",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-27769",
"datePublished": "2026-04-15T10:11:07.676Z",
"dateReserved": "2026-03-16T08:51:03.250Z",
"dateUpdated": "2026-04-15T13:08:35.452Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-21388 (GCVE-0-2026-21388)
Vulnerability from nvd – Published: 2026-04-09 10:09 – Updated: 2026-04-09 11:44
VLAI?
Title
Unbounded Request Body Read in MS Teams Plugin {{/lifecycle}} Webhook Endpoint
Summary
Mattermost Plugins versions <=2.3.1 fail to limit the request body size on the {{/lifecycle}} webhook endpoint which allows an authenticated attacker to cause memory exhaustion and denial of service via sending an oversized JSON payload. Mattermost Advisory ID: MMSA-2026-00610
Severity ?
CWE
- CWE-770 - Allocation of Resources Without Limits or Throttling
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
0 , ≤ 2.3.1
(semver)
Unaffected: 2.3.2.0 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-21388",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-09T11:44:48.420691Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-09T11:44:54.614Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "2.3.1",
"status": "affected",
"version": "0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "2.3.2.0"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Lorenzo Gallegos"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost Plugins versions \u003c=2.3.1 fail to limit the request body size on the {{/lifecycle}} webhook endpoint which allows an authenticated attacker to cause memory exhaustion and denial of service via sending an oversized JSON payload. Mattermost Advisory ID: MMSA-2026-00610"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "HIGH",
"attackVector": "NETWORK",
"availabilityImpact": "LOW",
"baseScore": 3.7,
"baseSeverity": "LOW",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-770",
"description": "CWE-770: Allocation of Resources Without Limits or Throttling",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-09T10:09:23.899Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00610",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost Plugins to versions 2.3.2.0 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00610",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67558"
],
"discovery": "{\"self\"=\u003e\"https://mattermost.atlassian.net/rest/api/2/customFieldOption/10557\", \"value\"=\u003e\"Internal\", \"id\"=\u003e\"10557\"}"
},
"title": "Unbounded Request Body Read in MS Teams Plugin {{/lifecycle}} Webhook Endpoint",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-21388",
"datePublished": "2026-04-09T10:09:23.899Z",
"dateReserved": "2026-02-11T20:56:06.579Z",
"dateUpdated": "2026-04-09T11:44:54.614Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-3115 (GCVE-0-2026-3115)
Vulnerability from nvd – Published: 2026-03-26 16:23 – Updated: 2026-03-26 17:51
VLAI?
Title
Guest users can view group member IDs without respecting view restrictions
Summary
Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to apply view restrictions when retrieving group member IDs, which allows authenticated guest users to enumerate user IDs outside their allowed visibility scope via the group retrieval endpoint.. Mattermost Advisory ID: MMSA-2026-00594
Severity ?
4.3 (Medium)
CWE
- CWE-863 - Incorrect Authorization
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.2.0 , ≤ 11.2.2
(semver)
Affected: 10.11.0 , ≤ 10.11.10 (semver) Affected: 11.4.0 , ≤ 11.4.0 (semver) Affected: 11.3.0 , ≤ 11.3.1 (semver) Unaffected: 11.5.0 Unaffected: 11.2.3 Unaffected: 10.11.11 Unaffected: 11.4.1 Unaffected: 11.3.2 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-3115",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-26T17:37:24.982329Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T17:51:14.689Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.2.2",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.10",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.2.3"
},
{
"status": "unaffected",
"version": "10.11.11"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "winfunc"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.2.x \u003c= 11.2.2, 10.11.x \u003c= 10.11.10, 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1 fail to apply view restrictions when retrieving group member IDs, which allows authenticated guest users to enumerate user IDs outside their allowed visibility scope via the group retrieval endpoint.. Mattermost Advisory ID: MMSA-2026-00594"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 4.3,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-863",
"description": "CWE-863: Incorrect Authorization",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T16:23:05.887Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00594",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.2.3, 10.11.11, 11.4.1, 11.3.2 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00594",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67354"
],
"discovery": "EXTERNAL"
},
"title": "Guest users can view group member IDs without respecting view restrictions",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-3115",
"datePublished": "2026-03-26T16:23:05.887Z",
"dateReserved": "2026-02-24T11:06:52.132Z",
"dateUpdated": "2026-03-26T17:51:14.689Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-3114 (GCVE-0-2026-3114)
Vulnerability from nvd – Published: 2026-03-26 16:21 – Updated: 2026-03-26 17:51
VLAI?
Title
Zip Bomb Denial of Service via Unrestricted Archive Decompression
Summary
Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to validate decompressed archive entry sizes during file extraction which allows authenticated users with file upload permissions to cause a denial of service via crafted zip archives containing highly compressed entries (zip bombs) that exhaust server memory.. Mattermost Advisory ID: MMSA-2026-00598
Severity ?
6.5 (Medium)
CWE
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.4.0 , ≤ 11.4.0
(semver)
Affected: 11.3.0 , ≤ 11.3.1 (semver) Affected: 11.2.0 , ≤ 11.2.3 (semver) Affected: 10.11.0 , ≤ 10.11.11 (semver) Unaffected: 11.5.0 Unaffected: 11.4.1 Unaffected: 11.3.2 Unaffected: 11.2.4 Unaffected: 10.11.12 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-3114",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-26T17:37:33.825174Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T17:51:14.833Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.2.3",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.11",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
},
{
"status": "unaffected",
"version": "11.2.4"
},
{
"status": "unaffected",
"version": "10.11.12"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "winfunc"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1, 11.2.x \u003c= 11.2.3, 10.11.x \u003c= 10.11.11 fail to validate decompressed archive entry sizes during file extraction which allows authenticated users with file upload permissions to cause a denial of service via crafted zip archives containing highly compressed entries (zip bombs) that exhaust server memory.. Mattermost Advisory ID: MMSA-2026-00598"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 6.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-409",
"description": "CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T16:21:19.421Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00598",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00598",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67378"
],
"discovery": "EXTERNAL"
},
"title": "Zip Bomb Denial of Service via Unrestricted Archive Decompression",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-3114",
"datePublished": "2026-03-26T16:21:19.421Z",
"dateReserved": "2026-02-24T11:01:47.197Z",
"dateUpdated": "2026-03-26T17:51:14.833Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-3113 (GCVE-0-2026-3113)
Vulnerability from nvd – Published: 2026-03-26 16:18 – Updated: 2026-03-26 17:51
VLAI?
Title
mmctl export download command doesn’t restrict permissions to created file to file owner
Summary
Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to set permissions on downloaded bulk export which allows other local users on the server to be able to read contents of the bulk export.. Mattermost Advisory ID: MMSA-2026-00593
Severity ?
5 (Medium)
CWE
- CWE-732 - Incorrect Permission Assignment for Critical Resource
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.4.0 , ≤ 11.4.0
(semver)
Affected: 11.3.0 , ≤ 11.3.1 (semver) Affected: 11.2.0 , ≤ 11.2.3 (semver) Affected: 10.11.0 , ≤ 10.11.11 (semver) Unaffected: 11.5.0 Unaffected: 11.4.1 Unaffected: 11.3.2 Unaffected: 11.2.4 Unaffected: 10.11.12 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-3113",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-26T17:37:56.431786Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T17:51:15.160Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.2.3",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.11",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
},
{
"status": "unaffected",
"version": "11.2.4"
},
{
"status": "unaffected",
"version": "10.11.12"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "winfunc"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1, 11.2.x \u003c= 11.2.3, 10.11.x \u003c= 10.11.11 fail to set permissions on downloaded bulk export which allows other local users on the server to be able to read contents of the bulk export.. Mattermost Advisory ID: MMSA-2026-00593"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "NONE",
"baseScore": 5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "HIGH",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-732",
"description": "CWE-732: Incorrect Permission Assignment for Critical Resource",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T16:18:06.693Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00593",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00593",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67334"
],
"discovery": "EXTERNAL"
},
"title": "mmctl export download command doesn\u2019t restrict permissions to created file to file owner",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-3113",
"datePublished": "2026-03-26T16:18:06.693Z",
"dateReserved": "2026-02-24T10:59:55.681Z",
"dateUpdated": "2026-03-26T17:51:15.160Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-3112 (GCVE-0-2026-3112)
Vulnerability from nvd – Published: 2026-03-26 16:29 – Updated: 2026-03-26 16:51
VLAI?
Title
Arbitrary File Read via Advanced Logging Support Packet
Summary
Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to validate Advanced Logging file target paths which allows system administrators to read arbitrary host files via malicious AdvancedLoggingJSON configuration in support packet generation. Mattermost Advisory ID: MMSA-2025-00562
Severity ?
6.8 (Medium)
CWE
- CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.4.0 , ≤ 11.4.0
(semver)
Affected: 11.3.0 , ≤ 11.3.1 (semver) Affected: 11.2.0 , ≤ 11.2.3 (semver) Affected: 10.11.0 , ≤ 10.11.11 (semver) Unaffected: 11.5.0 Unaffected: 11.4.1 Unaffected: 11.3.2 Unaffected: 11.2.4 Unaffected: 10.11.12 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-3112",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-26T16:51:09.685515Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T16:51:15.488Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.2.3",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.11",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
},
{
"status": "unaffected",
"version": "11.2.4"
},
{
"status": "unaffected",
"version": "10.11.12"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "mufeedvh"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1, 11.2.x \u003c= 11.2.3, 10.11.x \u003c= 10.11.11 fail to validate Advanced Logging file target paths which allows system administrators to read arbitrary host files via malicious AdvancedLoggingJSON configuration in support packet generation. Mattermost Advisory ID: MMSA-2025-00562"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 6.8,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "HIGH",
"integrityImpact": "NONE",
"privilegesRequired": "HIGH",
"scope": "CHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-22",
"description": "CWE-22: Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T16:29:54.399Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2025-00562",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12 or higher."
}
],
"source": {
"advisory": "MMSA-2025-00562",
"defect": [
"https://mattermost.atlassian.net/browse/MM-66788"
],
"discovery": "EXTERNAL"
},
"title": "Arbitrary File Read via Advanced Logging Support Packet",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-3112",
"datePublished": "2026-03-26T16:29:54.399Z",
"dateReserved": "2026-02-24T10:55:16.031Z",
"dateUpdated": "2026-03-26T16:51:15.488Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-3108 (GCVE-0-2026-3108)
Vulnerability from nvd – Published: 2026-03-26 16:16 – Updated: 2026-03-27 03:55
VLAI?
Title
Terminal Escape Injection in mmctl Report Posts Command
Summary
Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to sanitize user-controlled post content in the mmctl commands terminal output which allows attackers to manipulate administrator terminals via crafted messages containing ANSI and OSC escape sequences that enable screen manipulation, fake prompts, and clipboard hijacking.. Mattermost Advisory ID: MMSA-2026-00599
Severity ?
CWE
- CWE-150 - Improper Neutralization of Escape, Meta, or Control Sequences
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.2.0 , ≤ 11.2.2
(semver)
Affected: 10.11.0 , ≤ 10.11.10 (semver) Affected: 11.4.0 , ≤ 11.4.0 (semver) Affected: 11.3.0 , ≤ 11.3.1 (semver) Unaffected: 11.5.0 Unaffected: 11.2.3 Unaffected: 10.11.11 Unaffected: 11.4.1 Unaffected: 11.3.2 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-3108",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-26T00:00:00+00:00",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-27T03:55:41.498Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.2.2",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.10",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.2.3"
},
{
"status": "unaffected",
"version": "10.11.11"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "winfunc"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.2.x \u003c= 11.2.2, 10.11.x \u003c= 10.11.10, 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1 fail to sanitize user-controlled post content in the mmctl commands terminal output which allows attackers to manipulate administrator terminals via crafted messages containing ANSI and OSC escape sequences that enable screen manipulation, fake prompts, and clipboard hijacking.. Mattermost Advisory ID: MMSA-2026-00599"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "HIGH",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "CHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-150",
"description": "CWE-150: Improper Neutralization of Escape, Meta, or Control Sequences",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T16:16:49.790Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00599",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.2.3, 10.11.11, 11.4.1, 11.3.2 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00599",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67364"
],
"discovery": "EXTERNAL"
},
"title": "Terminal Escape Injection in mmctl Report Posts Command",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-3108",
"datePublished": "2026-03-26T16:16:49.790Z",
"dateReserved": "2026-02-24T10:50:40.507Z",
"dateUpdated": "2026-03-27T03:55:41.498Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-4274 (GCVE-0-2026-4274)
Vulnerability from nvd – Published: 2026-03-26 10:43 – Updated: 2026-03-26 13:58
VLAI?
Title
Insufficient authorization in shared channel membership sync grants team-level access instead of channel-level access
Summary
Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to restrict team-level access when processing membership sync from a remote cluster, which allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared channel via sending crafted membership sync messages that trigger team membership assignment. Mattermost Advisory ID: MMSA-2026-00574
Severity ?
5.4 (Medium)
CWE
- CWE-863 - Incorrect Authorization
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.2.0 , ≤ 11.2.2
(semver)
Affected: 10.11.0 , ≤ 10.11.10 (semver) Affected: 11.4.0 , ≤ 11.4.0 (semver) Affected: 11.3.0 , ≤ 11.3.1 (semver) Unaffected: 11.5.0 Unaffected: 11.2.3 Unaffected: 10.11.11 Unaffected: 11.4.1 Unaffected: 11.3.2 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-4274",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-26T13:58:33.420989Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T13:58:41.567Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.2.2",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.10",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.2.3"
},
{
"status": "unaffected",
"version": "10.11.11"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "daw10"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.2.x \u003c= 11.2.2, 10.11.x \u003c= 10.11.10, 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1 fail to restrict team-level access when processing membership sync from a remote cluster, which allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared channel via sending crafted membership sync messages that trigger team membership assignment. Mattermost Advisory ID: MMSA-2026-00574"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 5.4,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-863",
"description": "CWE-863: Incorrect Authorization",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T10:43:24.611Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00574",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.2.3, 10.11.11, 11.4.1, 11.3.2 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00574",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67099"
],
"discovery": "EXTERNAL"
},
"title": "Insufficient authorization in shared channel membership sync grants team-level access instead of channel-level access",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-4274",
"datePublished": "2026-03-26T10:43:24.611Z",
"dateReserved": "2026-03-16T15:18:50.150Z",
"dateUpdated": "2026-03-26T13:58:41.567Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-27659 (GCVE-0-2026-27659)
Vulnerability from nvd – Published: 2026-03-25 16:33 – Updated: 2026-03-25 17:39
VLAI?
Title
CSRF vulnerability in UpdateAccessControlPolicyActiveStatus endpoint
Summary
Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to properly validate CSRF tokens in the /api/v4/access_control_policies/{policy_id}/activate endpoint, which allows an attacker to trick an admin into changing access control policy active status via a crafted request.. Mattermost Advisory ID: MMSA-2026-00578
Severity ?
4.6 (Medium)
CWE
- CWE-352 - Cross-Site Request Forgery (CSRF)
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.2.0 , ≤ 11.2.2
(semver)
Affected: 10.11.0 , ≤ 10.11.10 (semver) Affected: 11.4.0 , ≤ 11.4.0 (semver) Affected: 11.3.0 , ≤ 11.3.1 (semver) Unaffected: 11.5.0 Unaffected: 11.2.3 Unaffected: 10.11.11 Unaffected: 11.4.1 Unaffected: 11.3.2 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-27659",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-25T17:39:20.789294Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-25T17:39:28.092Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.2.2",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.10",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.2.3"
},
{
"status": "unaffected",
"version": "10.11.11"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Joshua Rogers"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.2.x \u003c= 11.2.2, 10.11.x \u003c= 10.11.10, 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1 fail to properly validate CSRF tokens in the /api/v4/access_control_policies/{policy_id}/activate endpoint, which allows an attacker to trick an admin into changing access control policy active status via a crafted request.. Mattermost Advisory ID: MMSA-2026-00578"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 4.6,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-352",
"description": "CWE-352: Cross-Site Request Forgery (CSRF)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-25T16:33:32.724Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00578",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.2.3, 10.11.11, 11.4.1, 11.3.2 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00578",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67125"
],
"discovery": "EXTERNAL"
},
"title": "CSRF vulnerability in UpdateAccessControlPolicyActiveStatus endpoint",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-27659",
"datePublished": "2026-03-25T16:33:32.724Z",
"dateReserved": "2026-02-23T22:18:41.203Z",
"dateUpdated": "2026-03-25T17:39:28.092Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-27656 (GCVE-0-2026-27656)
Vulnerability from nvd – Published: 2026-03-25 16:28 – Updated: 2026-03-26 13:19
VLAI?
Title
Account Takeover via Substring Matching in OpenID Connect Authentication
Summary
Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to properly validate user identity in the OpenID {{IsSameUser()}} comparison logic, which allows an attacker to take over arbitrary user accounts via an overly permissive substring matching flaw in the user discovery flow.. Mattermost Advisory ID: MMSA-2026-00590
Severity ?
5.7 (Medium)
CWE
- CWE-303 - Incorrect Implementation of Authentication Algorithm
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.4.0 , ≤ 11.4.0
(semver)
Affected: 11.3.0 , ≤ 11.3.1 (semver) Affected: 11.2.0 , ≤ 11.2.3 (semver) Affected: 10.11.0 , ≤ 10.11.11 (semver) Unaffected: 11.5.0 Unaffected: 11.4.1 Unaffected: 11.3.2 Unaffected: 11.2.4 Unaffected: 10.11.12 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-27656",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-26T03:55:33.452102Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T13:19:52.338Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.2.3",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.11",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
},
{
"status": "unaffected",
"version": "11.2.4"
},
{
"status": "unaffected",
"version": "10.11.12"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Christopher Poile"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1, 11.2.x \u003c= 11.2.3, 10.11.x \u003c= 10.11.11 fail to properly validate user identity in the OpenID {{IsSameUser()}} comparison logic, which allows an attacker to take over arbitrary user accounts via an overly permissive substring matching flaw in the user discovery flow.. Mattermost Advisory ID: MMSA-2026-00590"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "HIGH",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 5.7,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "HIGH",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-303",
"description": "CWE-303: Incorrect Implementation of Authentication Algorithm",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-25T16:28:29.739Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00590",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00590",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67181"
],
"discovery": "{\"self\"=\u003e\"https://mattermost.atlassian.net/rest/api/2/customFieldOption/10557\", \"value\"=\u003e\"Internal\", \"id\"=\u003e\"10557\"}"
},
"title": "Account Takeover via Substring Matching in OpenID Connect Authentication",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-27656",
"datePublished": "2026-03-25T16:28:29.739Z",
"dateReserved": "2026-02-23T22:07:32.808Z",
"dateUpdated": "2026-03-26T13:19:52.338Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-26233 (GCVE-0-2026-26233)
Vulnerability from nvd – Published: 2026-03-25 16:24 – Updated: 2026-03-27 14:59
VLAI?
Title
Denial of Service via HTTP/2 single packet attack on login endpoint
Summary
Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to rate limit login requests which allows unauthenticated remote attackers to cause denial of service (server crash and restart) via HTTP/2 single packet attack with 100+ parallel login requests.. Mattermost Advisory ID: MMSA-2025-00566
Severity ?
4.3 (Medium)
CWE
- CWE-400 - Uncontrolled Resource Consumption
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.4.0 , ≤ 11.4.0
(semver)
Affected: 11.3.0 , ≤ 11.3.1 (semver) Affected: 11.2.0 , ≤ 11.2.3 (semver) Affected: 10.11.0 , ≤ 10.11.11 (semver) Unaffected: 11.5.0 Unaffected: 11.4.1 Unaffected: 11.3.2 Unaffected: 11.2.4 Unaffected: 10.11.12 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-26233",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-27T14:59:40.444232Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-27T14:59:50.732Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.2.3",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.11",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
},
{
"status": "unaffected",
"version": "11.2.4"
},
{
"status": "unaffected",
"version": "10.11.12"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Axel Larsson \u0026 Jakob Ristner"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1, 11.2.x \u003c= 11.2.3, 10.11.x \u003c= 10.11.11 fail to rate limit login requests which allows unauthenticated remote attackers to cause denial of service (server crash and restart) via HTTP/2 single packet attack with 100+ parallel login requests.. Mattermost Advisory ID: MMSA-2025-00566"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "LOW",
"baseScore": 4.3,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-400",
"description": "CWE-400 Uncontrolled Resource Consumption",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-25T16:24:47.694Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2025-00566",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12 or higher."
}
],
"source": {
"advisory": "MMSA-2025-00566",
"defect": [
"https://mattermost.atlassian.net/browse/MM-66885"
],
"discovery": "EXTERNAL"
},
"title": "Denial of Service via HTTP/2 single packet attack on login endpoint",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-26233",
"datePublished": "2026-03-25T16:24:47.694Z",
"dateReserved": "2026-02-23T22:18:41.232Z",
"dateUpdated": "2026-03-27T14:59:50.732Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-20719 (GCVE-0-2026-20719)
Vulnerability from nvd – Published: 2026-03-25 16:30 – Updated: 2026-03-26 17:11
VLAI?
Title
DoS via URL Previews Rendering Malicious SVGs
Summary
Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to prevent rendering of external SVGs on link embeds which allows unauthenticated users to crash the Mattermost webapp and desktop app via creating an issue or PR on GitHub.. Mattermost Advisory ID: MMSA-2026-00595
Severity ?
4.3 (Medium)
CWE
- CWE-754 - Improper Check for Unusual or Exceptional Conditions
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.4.0 , ≤ 11.4.0
(semver)
Affected: 11.3.0 , ≤ 11.3.1 (semver) Affected: 11.2.0 , ≤ 11.2.3 (semver) Affected: 10.11.0 , ≤ 10.11.11 (semver) Unaffected: 11.5.0 Unaffected: 11.4.1 Unaffected: 11.3.2 Unaffected: 11.2.4 Unaffected: 10.11.12 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-20719",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-26T17:11:15.846505Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T17:11:21.474Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.2.3",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.11",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
},
{
"status": "unaffected",
"version": "11.2.4"
},
{
"status": "unaffected",
"version": "10.11.12"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "mk7120"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1, 11.2.x \u003c= 11.2.3, 10.11.x \u003c= 10.11.11 fail to prevent rendering of external SVGs on link embeds which allows unauthenticated users to crash the Mattermost webapp and desktop app via creating an issue or PR on GitHub.. Mattermost Advisory ID: MMSA-2026-00595"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "LOW",
"baseScore": 4.3,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-754",
"description": "CWE-754: Improper Check for Unusual or Exceptional Conditions",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-25T16:30:47.041Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00595",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00595",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67371"
],
"discovery": "EXTERNAL"
},
"title": "DoS via URL Previews Rendering Malicious SVGs",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-20719",
"datePublished": "2026-03-25T16:30:47.041Z",
"dateReserved": "2026-02-23T22:07:32.817Z",
"dateUpdated": "2026-03-26T17:11:21.474Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-2454 (GCVE-0-2026-2454)
Vulnerability from nvd – Published: 2026-03-16 20:10 – Updated: 2026-03-17 13:37
VLAI?
Title
DoS in Calls plugin via malformed msgpack in websocket request.
Summary
Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to handle incorrectly reported array lengths which allows malicious user to cause OOM errors and crash the server via sending corrupted msgpack frames within websocket messages to calls plugin. Mattermost Advisory ID: MMSA-2025-00537
Severity ?
5.8 (Medium)
CWE
- CWE-1287 - Improper Validation of Specified Type of Input
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.3.0 , ≤ 11.3.0
(semver)
Affected: 11.2.0 , ≤ 11.2.2 (semver) Affected: 10.11.0 , ≤ 10.11.10 (semver) Unaffected: 11.4.0 Unaffected: 11.3.1 Unaffected: 11.2.3 Unaffected: 10.11.11 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-2454",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-17T13:37:37.264945Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-17T13:37:43.947Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.3.0",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.2.2",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.10",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.4.0"
},
{
"status": "unaffected",
"version": "11.3.1"
},
{
"status": "unaffected",
"version": "11.2.3"
},
{
"status": "unaffected",
"version": "10.11.11"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "National Security Agency"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.3.x \u003c= 11.3.0, 11.2.x \u003c= 11.2.2, 10.11.x \u003c= 10.11.10 fail to handle incorrectly reported array lengths which allows malicious user to cause OOM errors and crash the server via sending corrupted msgpack frames within websocket messages to calls plugin. Mattermost Advisory ID: MMSA-2025-00537"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "LOW",
"baseScore": 5.8,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "CHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-1287",
"description": "CWE-1287: Improper Validation of Specified Type of Input",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-16T20:10:16.644Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2025-00537",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.4.0, 11.3.1, 11.2.3, 10.11.11 or higher."
}
],
"source": {
"advisory": "MMSA-2025-00537",
"defect": [
"https://mattermost.atlassian.net/browse/MM-66166"
],
"discovery": "EXTERNAL"
},
"title": "DoS in Calls plugin via malformed msgpack in websocket request."
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-2454",
"datePublished": "2026-03-16T20:10:16.644Z",
"dateReserved": "2026-02-13T10:11:47.778Z",
"dateUpdated": "2026-03-17T13:37:43.947Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-26230 (GCVE-0-2026-26230)
Vulnerability from nvd – Published: 2026-03-16 20:19 – Updated: 2026-03-17 13:37
VLAI?
Title
Team Admin Privilege Escalation to Demote Members to Guest
Summary
Mattermost versions 10.11.x <= 10.11.10 fail to properly validate permission requirements in the team member roles API endpoint which allows team administrators to demote members to guest role. Mattermost Advisory ID: MMSA-2025-00531
Severity ?
CWE
- CWE-863 - Incorrect Authorization
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
10.11.0 , ≤ 10.11.10
(semver)
Unaffected: 11.4.0 Unaffected: 10.11.11 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-26230",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-17T13:37:10.650822Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-17T13:37:17.914Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "10.11.10",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.4.0"
},
{
"status": "unaffected",
"version": "10.11.11"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "hackit_bharat"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 10.11.x \u003c= 10.11.10 fail to properly validate permission requirements in the team member roles API endpoint which allows team administrators to demote members to guest role. Mattermost Advisory ID: MMSA-2025-00531"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 3.8,
"baseSeverity": "LOW",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"privilegesRequired": "HIGH",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-863",
"description": "CWE-863: Incorrect Authorization",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-16T20:19:51.287Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2025-00531",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.4.0, 10.11.11 or higher."
}
],
"source": {
"advisory": "MMSA-2025-00531",
"defect": [
"https://mattermost.atlassian.net/browse/MM-66091"
],
"discovery": "EXTERNAL"
},
"title": "Team Admin Privilege Escalation to Demote Members to Guest"
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-26230",
"datePublished": "2026-03-16T20:19:51.287Z",
"dateReserved": "2026-02-13T10:39:47.088Z",
"dateUpdated": "2026-03-17T13:37:17.914Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-3590 (GCVE-0-2026-3590)
Vulnerability from cvelistv5 – Published: 2026-04-15 11:00 – Updated: 2026-04-15 14:00
VLAI?
Title
Race Condition in Guest Magic Link Authentication Allows Token Reuse
Summary
Mattermost versions 10.11.x <= 10.11.12, 11.5.x <= 11.5.0, 11.4.x <= 11.4.2, 11.3.x <= 11.3.2 fail to enforce atomic single-use consumption of guest magic link tokens, which allows an attacker with access to a valid magic link to establish multiple independent authenticated sessions via concurrent requests.. Mattermost Advisory ID: MMSA-2026-00624
Severity ?
6.5 (Medium)
CWE
- CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
10.11.0 , ≤ 10.11.12
(semver)
Affected: 11.5.0 , ≤ 11.5.0 (semver) Affected: 11.4.0 , ≤ 11.4.2 (semver) Affected: 11.3.0 , ≤ 11.3.2 (semver) Unaffected: 11.6.0 Unaffected: 10.11.13 Unaffected: 11.5.1 Unaffected: 11.4.3 Unaffected: 11.3.3 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-3590",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-15T14:00:15.919479Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-15T14:00:27.030Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "10.11.12",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.5.0",
"status": "affected",
"version": "11.5.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.4.2",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.2",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.6.0"
},
{
"status": "unaffected",
"version": "10.11.13"
},
{
"status": "unaffected",
"version": "11.5.1"
},
{
"status": "unaffected",
"version": "11.4.3"
},
{
"status": "unaffected",
"version": "11.3.3"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Edgar Bellot Mic\u00f3"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 10.11.x \u003c= 10.11.12, 11.5.x \u003c= 11.5.0, 11.4.x \u003c= 11.4.2, 11.3.x \u003c= 11.3.2 fail to enforce atomic single-use consumption of guest magic link tokens, which allows an attacker with access to a valid magic link to establish multiple independent authenticated sessions via concurrent requests.. Mattermost Advisory ID: MMSA-2026-00624"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 6.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-367",
"description": "CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-15T11:00:14.880Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00624",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.6.0, 10.11.13, 11.5.1, 11.4.3, 11.3.3 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00624",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67791"
],
"discovery": "EXTERNAL"
},
"title": "Race Condition in Guest Magic Link Authentication Allows Token Reuse",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-3590",
"datePublished": "2026-04-15T11:00:14.880Z",
"dateReserved": "2026-03-05T11:34:57.712Z",
"dateUpdated": "2026-04-15T14:00:27.030Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-28741 (GCVE-0-2026-28741)
Vulnerability from cvelistv5 – Published: 2026-04-15 10:13 – Updated: 2026-04-15 15:39
VLAI?
Title
CSRF Protection Bypass Allows Updating a User's Authentication Method
Summary
Mattermost versions 10.11.x <= 10.11.12, 11.5.x <= 11.5.0, 11.4.x <= 11.4.2, 11.3.x <= 11.3.2 fail to validate CSRF tokens on an authentication endpoint which allows an attacker to update a user's authentication method via a CSRF attack by tricking a user into visiting a malicious page. Mattermost Advisory ID: MMSA-2026-00625
Severity ?
6.8 (Medium)
CWE
- CWE-352 - Cross-Site Request Forgery (CSRF)
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
10.11.0 , ≤ 10.11.12
(semver)
Affected: 11.5.0 , ≤ 11.5.0 (semver) Affected: 11.4.0 , ≤ 11.4.2 (semver) Affected: 11.3.0 , ≤ 11.3.2 (semver) Unaffected: 10.11.13 Unaffected: 11.5.1 Unaffected: 11.4.3 Unaffected: 11.3.3 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-28741",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-15T15:39:07.449816Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-15T15:39:52.265Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "10.11.12",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.5.0",
"status": "affected",
"version": "11.5.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.4.2",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.2",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "10.11.13"
},
{
"status": "unaffected",
"version": "11.5.1"
},
{
"status": "unaffected",
"version": "11.4.3"
},
{
"status": "unaffected",
"version": "11.3.3"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Eva Sarafianou"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 10.11.x \u003c= 10.11.12, 11.5.x \u003c= 11.5.0, 11.4.x \u003c= 11.4.2, 11.3.x \u003c= 11.3.2 fail to validate CSRF tokens on an authentication endpoint which allows an attacker to update a user\u0027s authentication method via a CSRF attack by tricking a user into visiting a malicious page. Mattermost Advisory ID: MMSA-2026-00625"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "HIGH",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 6.8,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-352",
"description": "CWE-352: Cross-Site Request Forgery (CSRF)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-15T10:13:33.950Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00625",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 10.11.13, 11.5.1, 11.4.3, 11.3.3 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00625",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67789"
],
"discovery": "EXTERNAL"
},
"title": "CSRF Protection Bypass Allows Updating a User\u0027s Authentication Method",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-28741",
"datePublished": "2026-04-15T10:13:33.950Z",
"dateReserved": "2026-03-10T13:45:39.984Z",
"dateUpdated": "2026-04-15T15:39:52.265Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-27769 (GCVE-0-2026-27769)
Vulnerability from cvelistv5 – Published: 2026-04-15 10:11 – Updated: 2026-04-15 13:08
VLAI?
Title
Connected Workspaces: Malicious remote server can manipulate arbitrary user's status
Summary
Mattermost versions 10.11.x <= 10.11.12 fail to validate whether users were correctly owned by the correct Connected Workspace which allows a malicious remote server connected using the Conntexted Workspaces feature to change the displayed status of local users via the Connected Workspaces API.. Mattermost Advisory ID: MMSA-2026-00603
Severity ?
CWE
- CWE-862 - Missing Authorization
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
10.11.0 , ≤ 10.11.12
(semver)
Unaffected: 11.5.0 Unaffected: 10.11.13 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-27769",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-15T13:08:29.628271Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-15T13:08:35.452Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "10.11.12",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "10.11.13"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "daw10"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 10.11.x \u003c= 10.11.12 fail to validate whether users were correctly owned by the correct Connected Workspace which allows a malicious remote server connected using the Conntexted Workspaces feature to change the displayed status of local users via the Connected Workspaces API.. Mattermost Advisory ID: MMSA-2026-00603"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 2.7,
"baseSeverity": "LOW",
"confidentialityImpact": "NONE",
"integrityImpact": "LOW",
"privilegesRequired": "HIGH",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-862",
"description": "CWE-862: Missing Authorization",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-15T10:11:07.676Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00603",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 10.11.13 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00603",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67521"
],
"discovery": "EXTERNAL"
},
"title": "Connected Workspaces: Malicious remote server can manipulate arbitrary user\u0027s status",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-27769",
"datePublished": "2026-04-15T10:11:07.676Z",
"dateReserved": "2026-03-16T08:51:03.250Z",
"dateUpdated": "2026-04-15T13:08:35.452Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-21388 (GCVE-0-2026-21388)
Vulnerability from cvelistv5 – Published: 2026-04-09 10:09 – Updated: 2026-04-09 11:44
VLAI?
Title
Unbounded Request Body Read in MS Teams Plugin {{/lifecycle}} Webhook Endpoint
Summary
Mattermost Plugins versions <=2.3.1 fail to limit the request body size on the {{/lifecycle}} webhook endpoint which allows an authenticated attacker to cause memory exhaustion and denial of service via sending an oversized JSON payload. Mattermost Advisory ID: MMSA-2026-00610
Severity ?
CWE
- CWE-770 - Allocation of Resources Without Limits or Throttling
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
0 , ≤ 2.3.1
(semver)
Unaffected: 2.3.2.0 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-21388",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-09T11:44:48.420691Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-09T11:44:54.614Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "2.3.1",
"status": "affected",
"version": "0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "2.3.2.0"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Lorenzo Gallegos"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost Plugins versions \u003c=2.3.1 fail to limit the request body size on the {{/lifecycle}} webhook endpoint which allows an authenticated attacker to cause memory exhaustion and denial of service via sending an oversized JSON payload. Mattermost Advisory ID: MMSA-2026-00610"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "HIGH",
"attackVector": "NETWORK",
"availabilityImpact": "LOW",
"baseScore": 3.7,
"baseSeverity": "LOW",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-770",
"description": "CWE-770: Allocation of Resources Without Limits or Throttling",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-09T10:09:23.899Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00610",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost Plugins to versions 2.3.2.0 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00610",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67558"
],
"discovery": "{\"self\"=\u003e\"https://mattermost.atlassian.net/rest/api/2/customFieldOption/10557\", \"value\"=\u003e\"Internal\", \"id\"=\u003e\"10557\"}"
},
"title": "Unbounded Request Body Read in MS Teams Plugin {{/lifecycle}} Webhook Endpoint",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-21388",
"datePublished": "2026-04-09T10:09:23.899Z",
"dateReserved": "2026-02-11T20:56:06.579Z",
"dateUpdated": "2026-04-09T11:44:54.614Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-3112 (GCVE-0-2026-3112)
Vulnerability from cvelistv5 – Published: 2026-03-26 16:29 – Updated: 2026-03-26 16:51
VLAI?
Title
Arbitrary File Read via Advanced Logging Support Packet
Summary
Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to validate Advanced Logging file target paths which allows system administrators to read arbitrary host files via malicious AdvancedLoggingJSON configuration in support packet generation. Mattermost Advisory ID: MMSA-2025-00562
Severity ?
6.8 (Medium)
CWE
- CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.4.0 , ≤ 11.4.0
(semver)
Affected: 11.3.0 , ≤ 11.3.1 (semver) Affected: 11.2.0 , ≤ 11.2.3 (semver) Affected: 10.11.0 , ≤ 10.11.11 (semver) Unaffected: 11.5.0 Unaffected: 11.4.1 Unaffected: 11.3.2 Unaffected: 11.2.4 Unaffected: 10.11.12 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-3112",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-26T16:51:09.685515Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T16:51:15.488Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.2.3",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.11",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
},
{
"status": "unaffected",
"version": "11.2.4"
},
{
"status": "unaffected",
"version": "10.11.12"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "mufeedvh"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1, 11.2.x \u003c= 11.2.3, 10.11.x \u003c= 10.11.11 fail to validate Advanced Logging file target paths which allows system administrators to read arbitrary host files via malicious AdvancedLoggingJSON configuration in support packet generation. Mattermost Advisory ID: MMSA-2025-00562"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 6.8,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "HIGH",
"integrityImpact": "NONE",
"privilegesRequired": "HIGH",
"scope": "CHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-22",
"description": "CWE-22: Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T16:29:54.399Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2025-00562",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12 or higher."
}
],
"source": {
"advisory": "MMSA-2025-00562",
"defect": [
"https://mattermost.atlassian.net/browse/MM-66788"
],
"discovery": "EXTERNAL"
},
"title": "Arbitrary File Read via Advanced Logging Support Packet",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-3112",
"datePublished": "2026-03-26T16:29:54.399Z",
"dateReserved": "2026-02-24T10:55:16.031Z",
"dateUpdated": "2026-03-26T16:51:15.488Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-3115 (GCVE-0-2026-3115)
Vulnerability from cvelistv5 – Published: 2026-03-26 16:23 – Updated: 2026-03-26 17:51
VLAI?
Title
Guest users can view group member IDs without respecting view restrictions
Summary
Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to apply view restrictions when retrieving group member IDs, which allows authenticated guest users to enumerate user IDs outside their allowed visibility scope via the group retrieval endpoint.. Mattermost Advisory ID: MMSA-2026-00594
Severity ?
4.3 (Medium)
CWE
- CWE-863 - Incorrect Authorization
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.2.0 , ≤ 11.2.2
(semver)
Affected: 10.11.0 , ≤ 10.11.10 (semver) Affected: 11.4.0 , ≤ 11.4.0 (semver) Affected: 11.3.0 , ≤ 11.3.1 (semver) Unaffected: 11.5.0 Unaffected: 11.2.3 Unaffected: 10.11.11 Unaffected: 11.4.1 Unaffected: 11.3.2 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-3115",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-26T17:37:24.982329Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T17:51:14.689Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.2.2",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.10",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.2.3"
},
{
"status": "unaffected",
"version": "10.11.11"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "winfunc"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.2.x \u003c= 11.2.2, 10.11.x \u003c= 10.11.10, 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1 fail to apply view restrictions when retrieving group member IDs, which allows authenticated guest users to enumerate user IDs outside their allowed visibility scope via the group retrieval endpoint.. Mattermost Advisory ID: MMSA-2026-00594"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 4.3,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-863",
"description": "CWE-863: Incorrect Authorization",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T16:23:05.887Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00594",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.2.3, 10.11.11, 11.4.1, 11.3.2 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00594",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67354"
],
"discovery": "EXTERNAL"
},
"title": "Guest users can view group member IDs without respecting view restrictions",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-3115",
"datePublished": "2026-03-26T16:23:05.887Z",
"dateReserved": "2026-02-24T11:06:52.132Z",
"dateUpdated": "2026-03-26T17:51:14.689Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-3114 (GCVE-0-2026-3114)
Vulnerability from cvelistv5 – Published: 2026-03-26 16:21 – Updated: 2026-03-26 17:51
VLAI?
Title
Zip Bomb Denial of Service via Unrestricted Archive Decompression
Summary
Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to validate decompressed archive entry sizes during file extraction which allows authenticated users with file upload permissions to cause a denial of service via crafted zip archives containing highly compressed entries (zip bombs) that exhaust server memory.. Mattermost Advisory ID: MMSA-2026-00598
Severity ?
6.5 (Medium)
CWE
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.4.0 , ≤ 11.4.0
(semver)
Affected: 11.3.0 , ≤ 11.3.1 (semver) Affected: 11.2.0 , ≤ 11.2.3 (semver) Affected: 10.11.0 , ≤ 10.11.11 (semver) Unaffected: 11.5.0 Unaffected: 11.4.1 Unaffected: 11.3.2 Unaffected: 11.2.4 Unaffected: 10.11.12 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-3114",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-26T17:37:33.825174Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T17:51:14.833Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.2.3",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.11",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
},
{
"status": "unaffected",
"version": "11.2.4"
},
{
"status": "unaffected",
"version": "10.11.12"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "winfunc"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1, 11.2.x \u003c= 11.2.3, 10.11.x \u003c= 10.11.11 fail to validate decompressed archive entry sizes during file extraction which allows authenticated users with file upload permissions to cause a denial of service via crafted zip archives containing highly compressed entries (zip bombs) that exhaust server memory.. Mattermost Advisory ID: MMSA-2026-00598"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 6.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-409",
"description": "CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T16:21:19.421Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00598",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00598",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67378"
],
"discovery": "EXTERNAL"
},
"title": "Zip Bomb Denial of Service via Unrestricted Archive Decompression",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-3114",
"datePublished": "2026-03-26T16:21:19.421Z",
"dateReserved": "2026-02-24T11:01:47.197Z",
"dateUpdated": "2026-03-26T17:51:14.833Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-3113 (GCVE-0-2026-3113)
Vulnerability from cvelistv5 – Published: 2026-03-26 16:18 – Updated: 2026-03-26 17:51
VLAI?
Title
mmctl export download command doesn’t restrict permissions to created file to file owner
Summary
Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to set permissions on downloaded bulk export which allows other local users on the server to be able to read contents of the bulk export.. Mattermost Advisory ID: MMSA-2026-00593
Severity ?
5 (Medium)
CWE
- CWE-732 - Incorrect Permission Assignment for Critical Resource
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.4.0 , ≤ 11.4.0
(semver)
Affected: 11.3.0 , ≤ 11.3.1 (semver) Affected: 11.2.0 , ≤ 11.2.3 (semver) Affected: 10.11.0 , ≤ 10.11.11 (semver) Unaffected: 11.5.0 Unaffected: 11.4.1 Unaffected: 11.3.2 Unaffected: 11.2.4 Unaffected: 10.11.12 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-3113",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-26T17:37:56.431786Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T17:51:15.160Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.2.3",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.11",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
},
{
"status": "unaffected",
"version": "11.2.4"
},
{
"status": "unaffected",
"version": "10.11.12"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "winfunc"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1, 11.2.x \u003c= 11.2.3, 10.11.x \u003c= 10.11.11 fail to set permissions on downloaded bulk export which allows other local users on the server to be able to read contents of the bulk export.. Mattermost Advisory ID: MMSA-2026-00593"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "NONE",
"baseScore": 5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "HIGH",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-732",
"description": "CWE-732: Incorrect Permission Assignment for Critical Resource",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T16:18:06.693Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00593",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00593",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67334"
],
"discovery": "EXTERNAL"
},
"title": "mmctl export download command doesn\u2019t restrict permissions to created file to file owner",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-3113",
"datePublished": "2026-03-26T16:18:06.693Z",
"dateReserved": "2026-02-24T10:59:55.681Z",
"dateUpdated": "2026-03-26T17:51:15.160Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-3108 (GCVE-0-2026-3108)
Vulnerability from cvelistv5 – Published: 2026-03-26 16:16 – Updated: 2026-03-27 03:55
VLAI?
Title
Terminal Escape Injection in mmctl Report Posts Command
Summary
Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to sanitize user-controlled post content in the mmctl commands terminal output which allows attackers to manipulate administrator terminals via crafted messages containing ANSI and OSC escape sequences that enable screen manipulation, fake prompts, and clipboard hijacking.. Mattermost Advisory ID: MMSA-2026-00599
Severity ?
CWE
- CWE-150 - Improper Neutralization of Escape, Meta, or Control Sequences
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.2.0 , ≤ 11.2.2
(semver)
Affected: 10.11.0 , ≤ 10.11.10 (semver) Affected: 11.4.0 , ≤ 11.4.0 (semver) Affected: 11.3.0 , ≤ 11.3.1 (semver) Unaffected: 11.5.0 Unaffected: 11.2.3 Unaffected: 10.11.11 Unaffected: 11.4.1 Unaffected: 11.3.2 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-3108",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-26T00:00:00+00:00",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-27T03:55:41.498Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.2.2",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.10",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.2.3"
},
{
"status": "unaffected",
"version": "10.11.11"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "winfunc"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.2.x \u003c= 11.2.2, 10.11.x \u003c= 10.11.10, 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1 fail to sanitize user-controlled post content in the mmctl commands terminal output which allows attackers to manipulate administrator terminals via crafted messages containing ANSI and OSC escape sequences that enable screen manipulation, fake prompts, and clipboard hijacking.. Mattermost Advisory ID: MMSA-2026-00599"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "HIGH",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "CHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-150",
"description": "CWE-150: Improper Neutralization of Escape, Meta, or Control Sequences",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T16:16:49.790Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00599",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.2.3, 10.11.11, 11.4.1, 11.3.2 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00599",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67364"
],
"discovery": "EXTERNAL"
},
"title": "Terminal Escape Injection in mmctl Report Posts Command",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-3108",
"datePublished": "2026-03-26T16:16:49.790Z",
"dateReserved": "2026-02-24T10:50:40.507Z",
"dateUpdated": "2026-03-27T03:55:41.498Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-4274 (GCVE-0-2026-4274)
Vulnerability from cvelistv5 – Published: 2026-03-26 10:43 – Updated: 2026-03-26 13:58
VLAI?
Title
Insufficient authorization in shared channel membership sync grants team-level access instead of channel-level access
Summary
Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to restrict team-level access when processing membership sync from a remote cluster, which allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared channel via sending crafted membership sync messages that trigger team membership assignment. Mattermost Advisory ID: MMSA-2026-00574
Severity ?
5.4 (Medium)
CWE
- CWE-863 - Incorrect Authorization
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.2.0 , ≤ 11.2.2
(semver)
Affected: 10.11.0 , ≤ 10.11.10 (semver) Affected: 11.4.0 , ≤ 11.4.0 (semver) Affected: 11.3.0 , ≤ 11.3.1 (semver) Unaffected: 11.5.0 Unaffected: 11.2.3 Unaffected: 10.11.11 Unaffected: 11.4.1 Unaffected: 11.3.2 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-4274",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-26T13:58:33.420989Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T13:58:41.567Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.2.2",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.10",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.2.3"
},
{
"status": "unaffected",
"version": "10.11.11"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "daw10"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.2.x \u003c= 11.2.2, 10.11.x \u003c= 10.11.10, 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1 fail to restrict team-level access when processing membership sync from a remote cluster, which allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared channel via sending crafted membership sync messages that trigger team membership assignment. Mattermost Advisory ID: MMSA-2026-00574"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 5.4,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-863",
"description": "CWE-863: Incorrect Authorization",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T10:43:24.611Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00574",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.2.3, 10.11.11, 11.4.1, 11.3.2 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00574",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67099"
],
"discovery": "EXTERNAL"
},
"title": "Insufficient authorization in shared channel membership sync grants team-level access instead of channel-level access",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-4274",
"datePublished": "2026-03-26T10:43:24.611Z",
"dateReserved": "2026-03-16T15:18:50.150Z",
"dateUpdated": "2026-03-26T13:58:41.567Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-27659 (GCVE-0-2026-27659)
Vulnerability from cvelistv5 – Published: 2026-03-25 16:33 – Updated: 2026-03-25 17:39
VLAI?
Title
CSRF vulnerability in UpdateAccessControlPolicyActiveStatus endpoint
Summary
Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to properly validate CSRF tokens in the /api/v4/access_control_policies/{policy_id}/activate endpoint, which allows an attacker to trick an admin into changing access control policy active status via a crafted request.. Mattermost Advisory ID: MMSA-2026-00578
Severity ?
4.6 (Medium)
CWE
- CWE-352 - Cross-Site Request Forgery (CSRF)
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.2.0 , ≤ 11.2.2
(semver)
Affected: 10.11.0 , ≤ 10.11.10 (semver) Affected: 11.4.0 , ≤ 11.4.0 (semver) Affected: 11.3.0 , ≤ 11.3.1 (semver) Unaffected: 11.5.0 Unaffected: 11.2.3 Unaffected: 10.11.11 Unaffected: 11.4.1 Unaffected: 11.3.2 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-27659",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-25T17:39:20.789294Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-25T17:39:28.092Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.2.2",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.10",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.2.3"
},
{
"status": "unaffected",
"version": "10.11.11"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Joshua Rogers"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.2.x \u003c= 11.2.2, 10.11.x \u003c= 10.11.10, 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1 fail to properly validate CSRF tokens in the /api/v4/access_control_policies/{policy_id}/activate endpoint, which allows an attacker to trick an admin into changing access control policy active status via a crafted request.. Mattermost Advisory ID: MMSA-2026-00578"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 4.6,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-352",
"description": "CWE-352: Cross-Site Request Forgery (CSRF)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-25T16:33:32.724Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00578",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.2.3, 10.11.11, 11.4.1, 11.3.2 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00578",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67125"
],
"discovery": "EXTERNAL"
},
"title": "CSRF vulnerability in UpdateAccessControlPolicyActiveStatus endpoint",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-27659",
"datePublished": "2026-03-25T16:33:32.724Z",
"dateReserved": "2026-02-23T22:18:41.203Z",
"dateUpdated": "2026-03-25T17:39:28.092Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-20719 (GCVE-0-2026-20719)
Vulnerability from cvelistv5 – Published: 2026-03-25 16:30 – Updated: 2026-03-26 17:11
VLAI?
Title
DoS via URL Previews Rendering Malicious SVGs
Summary
Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to prevent rendering of external SVGs on link embeds which allows unauthenticated users to crash the Mattermost webapp and desktop app via creating an issue or PR on GitHub.. Mattermost Advisory ID: MMSA-2026-00595
Severity ?
4.3 (Medium)
CWE
- CWE-754 - Improper Check for Unusual or Exceptional Conditions
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.4.0 , ≤ 11.4.0
(semver)
Affected: 11.3.0 , ≤ 11.3.1 (semver) Affected: 11.2.0 , ≤ 11.2.3 (semver) Affected: 10.11.0 , ≤ 10.11.11 (semver) Unaffected: 11.5.0 Unaffected: 11.4.1 Unaffected: 11.3.2 Unaffected: 11.2.4 Unaffected: 10.11.12 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-20719",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-26T17:11:15.846505Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T17:11:21.474Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.2.3",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.11",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
},
{
"status": "unaffected",
"version": "11.2.4"
},
{
"status": "unaffected",
"version": "10.11.12"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "mk7120"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1, 11.2.x \u003c= 11.2.3, 10.11.x \u003c= 10.11.11 fail to prevent rendering of external SVGs on link embeds which allows unauthenticated users to crash the Mattermost webapp and desktop app via creating an issue or PR on GitHub.. Mattermost Advisory ID: MMSA-2026-00595"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "LOW",
"baseScore": 4.3,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-754",
"description": "CWE-754: Improper Check for Unusual or Exceptional Conditions",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-25T16:30:47.041Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00595",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00595",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67371"
],
"discovery": "EXTERNAL"
},
"title": "DoS via URL Previews Rendering Malicious SVGs",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-20719",
"datePublished": "2026-03-25T16:30:47.041Z",
"dateReserved": "2026-02-23T22:07:32.817Z",
"dateUpdated": "2026-03-26T17:11:21.474Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-27656 (GCVE-0-2026-27656)
Vulnerability from cvelistv5 – Published: 2026-03-25 16:28 – Updated: 2026-03-26 13:19
VLAI?
Title
Account Takeover via Substring Matching in OpenID Connect Authentication
Summary
Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to properly validate user identity in the OpenID {{IsSameUser()}} comparison logic, which allows an attacker to take over arbitrary user accounts via an overly permissive substring matching flaw in the user discovery flow.. Mattermost Advisory ID: MMSA-2026-00590
Severity ?
5.7 (Medium)
CWE
- CWE-303 - Incorrect Implementation of Authentication Algorithm
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.4.0 , ≤ 11.4.0
(semver)
Affected: 11.3.0 , ≤ 11.3.1 (semver) Affected: 11.2.0 , ≤ 11.2.3 (semver) Affected: 10.11.0 , ≤ 10.11.11 (semver) Unaffected: 11.5.0 Unaffected: 11.4.1 Unaffected: 11.3.2 Unaffected: 11.2.4 Unaffected: 10.11.12 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-27656",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-26T03:55:33.452102Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-26T13:19:52.338Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.2.3",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.11",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
},
{
"status": "unaffected",
"version": "11.2.4"
},
{
"status": "unaffected",
"version": "10.11.12"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Christopher Poile"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1, 11.2.x \u003c= 11.2.3, 10.11.x \u003c= 10.11.11 fail to properly validate user identity in the OpenID {{IsSameUser()}} comparison logic, which allows an attacker to take over arbitrary user accounts via an overly permissive substring matching flaw in the user discovery flow.. Mattermost Advisory ID: MMSA-2026-00590"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "HIGH",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 5.7,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "HIGH",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-303",
"description": "CWE-303: Incorrect Implementation of Authentication Algorithm",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-25T16:28:29.739Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00590",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00590",
"defect": [
"https://mattermost.atlassian.net/browse/MM-67181"
],
"discovery": "{\"self\"=\u003e\"https://mattermost.atlassian.net/rest/api/2/customFieldOption/10557\", \"value\"=\u003e\"Internal\", \"id\"=\u003e\"10557\"}"
},
"title": "Account Takeover via Substring Matching in OpenID Connect Authentication",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-27656",
"datePublished": "2026-03-25T16:28:29.739Z",
"dateReserved": "2026-02-23T22:07:32.808Z",
"dateUpdated": "2026-03-26T13:19:52.338Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-26233 (GCVE-0-2026-26233)
Vulnerability from cvelistv5 – Published: 2026-03-25 16:24 – Updated: 2026-03-27 14:59
VLAI?
Title
Denial of Service via HTTP/2 single packet attack on login endpoint
Summary
Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to rate limit login requests which allows unauthenticated remote attackers to cause denial of service (server crash and restart) via HTTP/2 single packet attack with 100+ parallel login requests.. Mattermost Advisory ID: MMSA-2025-00566
Severity ?
4.3 (Medium)
CWE
- CWE-400 - Uncontrolled Resource Consumption
Assigner
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.4.0 , ≤ 11.4.0
(semver)
Affected: 11.3.0 , ≤ 11.3.1 (semver) Affected: 11.2.0 , ≤ 11.2.3 (semver) Affected: 10.11.0 , ≤ 10.11.11 (semver) Unaffected: 11.5.0 Unaffected: 11.4.1 Unaffected: 11.3.2 Unaffected: 11.2.4 Unaffected: 10.11.12 |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-26233",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-27T14:59:40.444232Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-27T14:59:50.732Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.4.0",
"status": "affected",
"version": "11.4.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.3.1",
"status": "affected",
"version": "11.3.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.2.3",
"status": "affected",
"version": "11.2.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "10.11.11",
"status": "affected",
"version": "10.11.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "11.5.0"
},
{
"status": "unaffected",
"version": "11.4.1"
},
{
"status": "unaffected",
"version": "11.3.2"
},
{
"status": "unaffected",
"version": "11.2.4"
},
{
"status": "unaffected",
"version": "10.11.12"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Axel Larsson \u0026 Jakob Ristner"
}
],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1, 11.2.x \u003c= 11.2.3, 10.11.x \u003c= 10.11.11 fail to rate limit login requests which allows unauthenticated remote attackers to cause denial of service (server crash and restart) via HTTP/2 single packet attack with 100+ parallel login requests.. Mattermost Advisory ID: MMSA-2025-00566"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "LOW",
"baseScore": 4.3,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-400",
"description": "CWE-400 Uncontrolled Resource Consumption",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-25T16:24:47.694Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2025-00566",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.5.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12 or higher."
}
],
"source": {
"advisory": "MMSA-2025-00566",
"defect": [
"https://mattermost.atlassian.net/browse/MM-66885"
],
"discovery": "EXTERNAL"
},
"title": "Denial of Service via HTTP/2 single packet attack on login endpoint",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-26233",
"datePublished": "2026-03-25T16:24:47.694Z",
"dateReserved": "2026-02-23T22:18:41.232Z",
"dateUpdated": "2026-03-27T14:59:50.732Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}