CVE-2026-6986 (GCVE-0-2026-6986)
Vulnerability from cvelistv5 – Published: 2026-04-25 16:30 – Updated: 2026-04-27 13:36 X_Open Source
VLAI?
Title
Cesanta Mongoose GCM Authentication Tag tls_aes128.c mg_aes_gcm_decrypt signature verification
Summary
A security vulnerability has been detected in Cesanta Mongoose up to 7.20. This issue affects the function mg_aes_gcm_decrypt of the file /src/tls_aes128.c of the component GCM Authentication Tag Handler. Such manipulation leads to improper verification of cryptographic signature. The attack may be performed from remote. A high complexity level is associated with this attack. The exploitability is assessed as difficult. The exploit has been disclosed publicly and may be used. Upgrading to version 7.21 is capable of addressing this issue. It is advisable to upgrade the affected component. VulDB has contacted the vendor early and they confirmed quickly, that this issue got fixed already.
Severity ?
CWE
Assigner
References
| URL | Tags | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
|||||||||||||||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Cesanta | Mongoose |
Affected:
7.0
Affected: 7.1 Affected: 7.2 Affected: 7.3 Affected: 7.4 Affected: 7.5 Affected: 7.6 Affected: 7.7 Affected: 7.8 Affected: 7.9 Affected: 7.10 Affected: 7.11 Affected: 7.12 Affected: 7.13 Affected: 7.14 Affected: 7.15 Affected: 7.16 Affected: 7.17 Affected: 7.18 Affected: 7.19 Affected: 7.20 Unaffected: 7.21 cpe:2.3:a:cesanta:mongoose:*:*:*:*:*:*:*:* |
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-6986",
"options": [
{
"Exploitation": "poc"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-27T13:33:26.520467Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-27T13:36:06.578Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"cpes": [
"cpe:2.3:a:cesanta:mongoose:*:*:*:*:*:*:*:*"
],
"modules": [
"GCM Authentication Tag Handler"
],
"product": "Mongoose",
"vendor": "Cesanta",
"versions": [
{
"status": "affected",
"version": "7.0"
},
{
"status": "affected",
"version": "7.1"
},
{
"status": "affected",
"version": "7.2"
},
{
"status": "affected",
"version": "7.3"
},
{
"status": "affected",
"version": "7.4"
},
{
"status": "affected",
"version": "7.5"
},
{
"status": "affected",
"version": "7.6"
},
{
"status": "affected",
"version": "7.7"
},
{
"status": "affected",
"version": "7.8"
},
{
"status": "affected",
"version": "7.9"
},
{
"status": "affected",
"version": "7.10"
},
{
"status": "affected",
"version": "7.11"
},
{
"status": "affected",
"version": "7.12"
},
{
"status": "affected",
"version": "7.13"
},
{
"status": "affected",
"version": "7.14"
},
{
"status": "affected",
"version": "7.15"
},
{
"status": "affected",
"version": "7.16"
},
{
"status": "affected",
"version": "7.17"
},
{
"status": "affected",
"version": "7.18"
},
{
"status": "affected",
"version": "7.19"
},
{
"status": "affected",
"version": "7.20"
},
{
"status": "unaffected",
"version": "7.21"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "reporter",
"value": "dwbruijn (VulDB User)"
},
{
"lang": "en",
"type": "coordinator",
"value": "VulDB CNA Team"
}
],
"descriptions": [
{
"lang": "en",
"value": "A security vulnerability has been detected in Cesanta Mongoose up to 7.20. This issue affects the function mg_aes_gcm_decrypt of the file /src/tls_aes128.c of the component GCM Authentication Tag Handler. Such manipulation leads to improper verification of cryptographic signature. The attack may be performed from remote. A high complexity level is associated with this attack. The exploitability is assessed as difficult. The exploit has been disclosed publicly and may be used. Upgrading to version 7.21 is capable of addressing this issue. It is advisable to upgrade the affected component. VulDB has contacted the vendor early and they confirmed quickly, that this issue got fixed already."
}
],
"metrics": [
{
"cvssV4_0": {
"baseScore": 6.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P",
"version": "4.0"
}
},
{
"cvssV3_1": {
"baseScore": 3.7,
"baseSeverity": "LOW",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C",
"version": "3.1"
}
},
{
"cvssV3_0": {
"baseScore": 3.7,
"baseSeverity": "LOW",
"vectorString": "CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C",
"version": "3.0"
}
},
{
"cvssV2_0": {
"baseScore": 2.6,
"vectorString": "AV:N/AC:H/Au:N/C:N/I:P/A:N/E:POC/RL:OF/RC:C",
"version": "2.0"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-347",
"description": "Improper Verification of Cryptographic Signature",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-345",
"description": "Insufficient Verification of Data Authenticity",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-25T16:30:13.067Z",
"orgId": "1af790b2-7ee1-4545-860a-a788eba489b5",
"shortName": "VulDB"
},
"references": [
{
"name": "VDB-359529 | Cesanta Mongoose GCM Authentication Tag tls_aes128.c mg_aes_gcm_decrypt signature verification",
"tags": [
"vdb-entry",
"technical-description"
],
"url": "https://vuldb.com/vuln/359529"
},
{
"name": "VDB-359529 | CTI Indicators (IOB, IOC, IOA)",
"tags": [
"signature",
"permissions-required"
],
"url": "https://vuldb.com/vuln/359529/cti"
},
{
"name": "Submit #796231 | Cesanta Mongoose 7.20 Improper Verification of Cryptographic Signature",
"tags": [
"third-party-advisory"
],
"url": "https://vuldb.com/submit/796231"
},
{
"tags": [
"exploit"
],
"url": "https://github.com/dwBruijn/CVEs/blob/main/Mongoose/AESGCM.md"
},
{
"tags": [
"patch"
],
"url": "https://github.com/cesanta/mongoose/releases/tag/7.21"
}
],
"tags": [
"x_open-source"
],
"timeline": [
{
"lang": "en",
"time": "2026-04-24T00:00:00.000Z",
"value": "Advisory disclosed"
},
{
"lang": "en",
"time": "2026-04-24T02:00:00.000Z",
"value": "VulDB entry created"
},
{
"lang": "en",
"time": "2026-04-24T21:18:01.000Z",
"value": "VulDB entry last update"
}
],
"title": "Cesanta Mongoose GCM Authentication Tag tls_aes128.c mg_aes_gcm_decrypt signature verification"
}
},
"cveMetadata": {
"assignerOrgId": "1af790b2-7ee1-4545-860a-a788eba489b5",
"assignerShortName": "VulDB",
"cveId": "CVE-2026-6986",
"datePublished": "2026-04-25T16:30:13.067Z",
"dateReserved": "2026-04-24T19:12:51.609Z",
"dateUpdated": "2026-04-27T13:36:06.578Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-6986",
"date": "2026-04-27",
"epss": "0.00015",
"percentile": "0.02981"
},
"nvd": "{\"cve\":{\"id\":\"CVE-2026-6986\",\"sourceIdentifier\":\"cna@vuldb.com\",\"published\":\"2026-04-25T17:16:33.700\",\"lastModified\":\"2026-04-25T17:16:33.700\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"A security vulnerability has been detected in Cesanta Mongoose up to 7.20. This issue affects the function mg_aes_gcm_decrypt of the file /src/tls_aes128.c of the component GCM Authentication Tag Handler. Such manipulation leads to improper verification of cryptographic signature. The attack may be performed from remote. A high complexity level is associated with this attack. The exploitability is assessed as difficult. The exploit has been disclosed publicly and may be used. Upgrading to version 7.21 is capable of addressing this issue. It is advisable to upgrade the affected component. VulDB has contacted the vendor early and they confirmed quickly, that this issue got fixed already.\"}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"cna@vuldb.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X\",\"baseScore\":6.3,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"HIGH\",\"attackRequirements\":\"NONE\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"vulnConfidentialityImpact\":\"NONE\",\"vulnIntegrityImpact\":\"LOW\",\"vulnAvailabilityImpact\":\"NONE\",\"subConfidentialityImpact\":\"NONE\",\"subIntegrityImpact\":\"NONE\",\"subAvailabilityImpact\":\"NONE\",\"exploitMaturity\":\"PROOF_OF_CONCEPT\",\"confidentialityRequirement\":\"NOT_DEFINED\",\"integrityRequirement\":\"NOT_DEFINED\",\"availabilityRequirement\":\"NOT_DEFINED\",\"modifiedAttackVector\":\"NOT_DEFINED\",\"modifiedAttackComplexity\":\"NOT_DEFINED\",\"modifiedAttackRequirements\":\"NOT_DEFINED\",\"modifiedPrivilegesRequired\":\"NOT_DEFINED\",\"modifiedUserInteraction\":\"NOT_DEFINED\",\"modifiedVulnConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedVulnIntegrityImpact\":\"NOT_DEFINED\",\"modifiedVulnAvailabilityImpact\":\"NOT_DEFINED\",\"modifiedSubConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedSubIntegrityImpact\":\"NOT_DEFINED\",\"modifiedSubAvailabilityImpact\":\"NOT_DEFINED\",\"Safety\":\"NOT_DEFINED\",\"Automatable\":\"NOT_DEFINED\",\"Recovery\":\"NOT_DEFINED\",\"valueDensity\":\"NOT_DEFINED\",\"vulnerabilityResponseEffort\":\"NOT_DEFINED\",\"providerUrgency\":\"NOT_DEFINED\"}}],\"cvssMetricV31\":[{\"source\":\"cna@vuldb.com\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N\",\"baseScore\":3.7,\"baseSeverity\":\"LOW\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"LOW\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":2.2,\"impactScore\":1.4}],\"cvssMetricV2\":[{\"source\":\"cna@vuldb.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"2.0\",\"vectorString\":\"AV:N/AC:H/Au:N/C:N/I:P/A:N\",\"baseScore\":2.6,\"accessVector\":\"NETWORK\",\"accessComplexity\":\"HIGH\",\"authentication\":\"NONE\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"PARTIAL\",\"availabilityImpact\":\"NONE\"},\"baseSeverity\":\"LOW\",\"exploitabilityScore\":4.9,\"impactScore\":2.9,\"acInsufInfo\":false,\"obtainAllPrivilege\":false,\"obtainUserPrivilege\":false,\"obtainOtherPrivilege\":false,\"userInteractionRequired\":false}]},\"weaknesses\":[{\"source\":\"cna@vuldb.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-345\"},{\"lang\":\"en\",\"value\":\"CWE-347\"}]}],\"references\":[{\"url\":\"https://github.com/cesanta/mongoose/releases/tag/7.21\",\"source\":\"cna@vuldb.com\"},{\"url\":\"https://github.com/dwBruijn/CVEs/blob/main/Mongoose/AESGCM.md\",\"source\":\"cna@vuldb.com\"},{\"url\":\"https://vuldb.com/submit/796231\",\"source\":\"cna@vuldb.com\"},{\"url\":\"https://vuldb.com/vuln/359529\",\"source\":\"cna@vuldb.com\"},{\"url\":\"https://vuldb.com/vuln/359529/cti\",\"source\":\"cna@vuldb.com\"}]}}"
}
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
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…
Loading…