CVE-2026-47245 (GCVE-0-2026-47245)
Vulnerability from cvelistv5 – Published: 2026-08-18 15:51 – Updated: 2026-08-18 17:37
VLAI
EPSS
VEX
Title
MyBB: Buddy list corruption
Summary
MyBB is free and open source forum software. Prior to 1.8.40, the User CP Buddy/Ignore List component does not validate reciprocal buddy-list updates correctly. The usercp.php?action=do_editlists delete handler removes the selected entry from the acting user's list and then updates mybb_users.buddylist for the target account. The reciprocal update searches for the deleted target UID instead of the acting user's UID and uses the unchecked array_search() return value as an array key. A false result can be converted to index 0, removing the target account's first stored buddy while leaving the actual reciprocal entry unchanged. The uniquely identifying implementation details include false converted to index 0. This issue is fixed in version 1.8.40.
Severity
4.3 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-18 17:37 UTC
CWE
- CWE-252 - Unchecked Return Value
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/mybb/mybb/security/advisories/… | x_refsource_CONFIRM |
| https://github.com/mybb/mybb/commit/0557718f27503… | x_refsource_MISC |
| https://github.com/mybb/mybb/releases/tag/mybb_1840 | x_refsource_MISC |
| https://mybb.com/versions/1.8.40 | x_refsource_MISC |
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-47245",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-08-18T17:37:14.548923Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-08-18T17:37:22.369Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "mybb",
"vendor": "mybb",
"versions": [
{
"status": "affected",
"version": "\u003c 1.8.40"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "MyBB is free and open source forum software. Prior to 1.8.40, the User CP Buddy/Ignore List component does not validate reciprocal buddy-list updates correctly. The usercp.php?action=do_editlists delete handler removes the selected entry from the acting user\u0027s list and then updates mybb_users.buddylist for the target account. The reciprocal update searches for the deleted target UID instead of the acting user\u0027s UID and uses the unchecked array_search() return value as an array key. A false result can be converted to index 0, removing the target account\u0027s first stored buddy while leaving the actual reciprocal entry unchanged. The uniquely identifying implementation details include false converted to index 0. This issue is fixed in version 1.8.40."
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 4.3,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "LOW",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N",
"version": "3.1"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-252",
"description": "CWE-252: Unchecked Return Value",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-18T15:51:33.857Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/mybb/mybb/security/advisories/GHSA-w8gm-j57p-jqpc",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/mybb/mybb/security/advisories/GHSA-w8gm-j57p-jqpc"
},
{
"name": "https://github.com/mybb/mybb/commit/0557718f27503034fb1c2768729a2fb8239bba65",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/mybb/mybb/commit/0557718f27503034fb1c2768729a2fb8239bba65"
},
{
"name": "https://github.com/mybb/mybb/releases/tag/mybb_1840",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/mybb/mybb/releases/tag/mybb_1840"
},
{
"name": "https://mybb.com/versions/1.8.40",
"tags": [
"x_refsource_MISC"
],
"url": "https://mybb.com/versions/1.8.40"
}
],
"source": {
"advisory": "GHSA-w8gm-j57p-jqpc",
"discovery": "UNKNOWN"
},
"title": "MyBB: Buddy list corruption"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-47245",
"datePublished": "2026-08-18T15:51:33.857Z",
"dateReserved": "2026-05-18T22:54:18.272Z",
"dateUpdated": "2026-08-18T17:37:22.369Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-47245",
"date": "2026-08-24",
"epss": "0.00269",
"percentile": "0.18502"
},
"nvd": "{\"cve\":{\"id\":\"CVE-2026-47245\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-08-18T16:17:09.507\",\"lastModified\":\"2026-08-18T18:17:38.950\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"MyBB is free and open source forum software. Prior to 1.8.40, the User CP Buddy/Ignore List component does not validate reciprocal buddy-list updates correctly. The usercp.php?action=do_editlists delete handler removes the selected entry from the acting user\u0027s list and then updates mybb_users.buddylist for the target account. The reciprocal update searches for the deleted target UID instead of the acting user\u0027s UID and uses the unchecked array_search() return value as an array key. A false result can be converted to index 0, removing the target account\u0027s first stored buddy while leaving the actual reciprocal entry unchanged. The uniquely identifying implementation details include false converted to index 0. This issue is fixed in version 1.8.40.\"}],\"affected\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"mybb\",\"product\":\"mybb\",\"versions\":[{\"version\":\"\u003c 1.8.40\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N\",\"baseScore\":4.3,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"LOW\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":2.8,\"impactScore\":1.4}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-08-18T17:37:14.548923Z\",\"id\":\"CVE-2026-47245\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-252\"}]}],\"references\":[{\"url\":\"https://github.com/mybb/mybb/commit/0557718f27503034fb1c2768729a2fb8239bba65\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/mybb/mybb/releases/tag/mybb_1840\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/mybb/mybb/security/advisories/GHSA-w8gm-j57p-jqpc\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://mybb.com/versions/1.8.40\",\"source\":\"security-advisories@github.com\"}]}}",
"vulnrichment": {
"containers": "{\"cna\": {\"title\": \"MyBB: Buddy list corruption\", \"problemTypes\": [{\"descriptions\": [{\"cweId\": \"CWE-252\", \"lang\": \"en\", \"description\": \"CWE-252: Unchecked Return Value\", \"type\": \"CWE\"}]}], \"metrics\": [{\"cvssV3_1\": {\"attackComplexity\": \"LOW\", \"attackVector\": \"NETWORK\", \"availabilityImpact\": \"NONE\", \"baseScore\": 4.3, \"baseSeverity\": \"MEDIUM\", \"confidentialityImpact\": \"NONE\", \"integrityImpact\": \"LOW\", \"privilegesRequired\": \"LOW\", \"scope\": \"UNCHANGED\", \"userInteraction\": \"NONE\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N\", \"version\": \"3.1\"}}], \"references\": [{\"name\": \"https://github.com/mybb/mybb/security/advisories/GHSA-w8gm-j57p-jqpc\", \"tags\": [\"x_refsource_CONFIRM\"], \"url\": \"https://github.com/mybb/mybb/security/advisories/GHSA-w8gm-j57p-jqpc\"}, {\"name\": \"https://github.com/mybb/mybb/commit/0557718f27503034fb1c2768729a2fb8239bba65\", \"tags\": [\"x_refsource_MISC\"], \"url\": \"https://github.com/mybb/mybb/commit/0557718f27503034fb1c2768729a2fb8239bba65\"}, {\"name\": \"https://github.com/mybb/mybb/releases/tag/mybb_1840\", \"tags\": [\"x_refsource_MISC\"], \"url\": \"https://github.com/mybb/mybb/releases/tag/mybb_1840\"}, {\"name\": \"https://mybb.com/versions/1.8.40\", \"tags\": [\"x_refsource_MISC\"], \"url\": \"https://mybb.com/versions/1.8.40\"}], \"affected\": [{\"vendor\": \"mybb\", \"product\": \"mybb\", \"versions\": [{\"version\": \"\u003c 1.8.40\", \"status\": \"affected\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-08-18T15:51:33.857Z\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"MyBB is free and open source forum software. Prior to 1.8.40, the User CP Buddy/Ignore List component does not validate reciprocal buddy-list updates correctly. The usercp.php?action=do_editlists delete handler removes the selected entry from the acting user\u0027s list and then updates mybb_users.buddylist for the target account. The reciprocal update searches for the deleted target UID instead of the acting user\u0027s UID and uses the unchecked array_search() return value as an array key. A false result can be converted to index 0, removing the target account\u0027s first stored buddy while leaving the actual reciprocal entry unchanged. The uniquely identifying implementation details include false converted to index 0. This issue is fixed in version 1.8.40.\"}], \"source\": {\"advisory\": \"GHSA-w8gm-j57p-jqpc\", \"discovery\": \"UNKNOWN\"}}, \"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-47245\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-08-18T17:37:14.548923Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-08-18T17:37:17.763Z\"}}]}",
"cveMetadata": "{\"cveId\": \"CVE-2026-47245\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"state\": \"PUBLISHED\", \"assignerShortName\": \"GitHub_M\", \"dateReserved\": \"2026-05-18T22:54:18.272Z\", \"datePublished\": \"2026-08-18T15:51:33.857Z\", \"dateUpdated\": \"2026-08-18T17:37:22.369Z\"}",
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Loading…
Loading…