{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-93851", "assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee", "state": "PUBLISHED", "assignerShortName": "Mattermost", "dateReserved": "2026-09-18T18:43:37.800Z", "datePublished": "2026-10-28T21:41:15.727Z", "dateUpdated": "2026-10-28T21:41:15.727Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "product": "Mattermost", "vendor": "Mattermost", "versions": [{"lessThanOrEqual": "11.9.1", "status": "affected", "version": "11.9.0", "versionType": "semver"}, {"lessThanOrEqual": "11.8.5", "status": "affected", "version": "11.8.0", "versionType": "semver"}, {"lessThanOrEqual": "11.7.10", "status": "affected", "version": "11.7.0", "versionType": "semver"}, {"version": "11.10.0", "status": "unaffected"}, {"version": "11.9.2", "status": "unaffected"}, {"version": "11.8.6", "status": "unaffected"}, {"version": "11.7.11", "status": "unaffected"}]}], "credits": [{"lang": "en", "type": "finder", "value": "z01dberg"}], "descriptions": [{"lang": "en", "value": "Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10 fail to validate the target post ID in the Agents plugin's mention reminder component, which allows an authenticated user who can post in a channel visible to a system administrator to cause the administrator's browser to send an unintended API request, resulting in replacement of an installed plugin and code execution on the server, via a crafted post containing a forged mention reminder that the administrator clicks. Mattermost Advisory ID: MMSA-2026-00742"}], "metrics": [{"cvssV3_1": {"attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "LOW", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH", "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H", "baseSeverity": "HIGH", "baseScore": 8}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "description": "CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')", "cweId": "CWE-22"}]}], "references": [{"url": "https://mattermost.com/security-updates", "name": "MMSA-2026-00742", "tags": ["vendor-advisory"]}], "solutions": [{"value": "Update Mattermost to versions 11.10.0, 11.9.2, 11.8.6, 11.7.11 or higher.", "lang": "en"}], "source": {"advisory": "MMSA-2026-00742", "defect": ["https://mattermost.atlassian.net/browse/MM-69957"], "discovery": "EXTERNAL"}, "title": "Path traversal in Mattermost Agents plugin mention reminder allows plugin replacement via crafted post", "providerMetadata": {"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee", "shortName": "Mattermost", "dateUpdated": "2026-10-28T21:41:15.727Z"}, "x_generator": {"engine": "cvelib 1.8.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Mattermost", "vendor": "Mattermost", "versions": [{"lessThanOrEqual": "11.9.1", "status": "affected", "version": "11.9.0", "versionType": "semver"}, {"lessThanOrEqual": "11.8.5", "status": "affected", "version": "11.8.0", "versionType": "semver"}, {"lessThanOrEqual": "11.7.10", "status": "affected", "version": "11.7.0", "versionType": "semver"}, {"status": "unaffected", "version": "11.10.0"}, {"status": "unaffected", "version": "11.9.2"}, {"status": "unaffected", "version": "11.8.6"}, {"status": "unaffected", "version": "11.7.11"}]}], "source": "responsibledisclosure@mattermost.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10 fail to validate the target post ID in the Agents plugin's mention reminder component, which allows an authenticated user who can post in a channel visible to a system administrator to cause the administrator's browser to send an unintended API request, resulting in replacement of an installed plugin and code execution on the server, via a crafted post containing a forged mention reminder that the administrator clicks. Mattermost Advisory ID: MMSA-2026-00742"}], "id": "CVE-2026-93851", "lastModified": "2026-10-28T22:17:17.310", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.0, "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"}, "exploitabilityScore": 1.3, "impactScore": 6.0, "source": "responsibledisclosure@mattermost.com", "type": "Secondary"}]}, "published": "2026-10-28T22:17:17.310", "references": [{"source": "responsibledisclosure@mattermost.com", "url": "https://mattermost.com/security-updates"}], "sourceIdentifier": "responsibledisclosure@mattermost.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-22"}], "source": "responsibledisclosure@mattermost.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[11.9.0,11.9.1]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[11.8.0,11.8.5]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[11.7.0,11.7.10]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "11.10.0"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "11.9.2"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "11.8.6"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "11.7.11"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Mattermost", "source": "cna", "vendor": "Mattermost"}, "product": "mattermost", "vendor": "mattermost"}], "created": "2026-10-28T22:45:15.015213+00:00", "updated": "2026-10-28T23:15:14.342282+00:00", "vendors": ["mattermost", "mattermost$PRODUCT$mattermost"]}