CVE-2026-20796

{"id": "CVE-2026-20796", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "responsibledisclosure@mattermost.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 3.1, "attackVector": "NETWORK", "baseSeverity": "LOW", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "LOW"}, "impactScore": 1.4, "exploitabilityScore": 1.6}]}, "published": "2026-02-13T11:16:10.280", "references": [{"url": "https://mattermost.com/security-updates", "tags": ["Vendor Advisory"], "source": "responsibledisclosure@mattermost.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "responsibledisclosure@mattermost.com", "description": [{"lang": "en", "value": "CWE-367"}]}], "descriptions": [{"lang": "en", "value": "Mattermost versions 10.11.x <= 10.11.9 fail to properly validate channel membership at the time of data retrieval which allows a deactivated user to learn team names they should not have access to via a race condition in the /common_teams API endpoint.. Mattermost Advisory ID: MMSA-2025-00549"}, {"lang": "es", "value": "Las versiones de Mattermost 10.11.x &lt;= 10.11.9 no validan correctamente la membres\u00eda del canal en el momento de la recuperaci\u00f3n de datos, lo que permite a un usuario desactivado conocer nombres de equipos a los que no deber\u00eda tener acceso a trav\u00e9s de una condici\u00f3n de carrera en el endpoint de la API /common_teams. ID de Aviso de Mattermost: MMSA-2025-00549"}], "lastModified": "2026-02-23T15:53:11.073", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "92B0F8BD-06A1-4B39-95C5-4FB5A195F1C4", "versionEndExcluding": "10.11.10", "versionStartIncluding": "10.11.0"}], "operator": "OR"}]}], "sourceIdentifier": "responsibledisclosure@mattermost.com"}