FKIE_CVE-2026-20796

Vulnerability from fkie_nvd - Published: 2026-02-13 11:16 - Updated: 2026-02-23 15:53
Severity ?
3.1 (Low) - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
Summary
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
References
responsibledisclosure@mattermost.comhttps://mattermost.com/security-updatesVendor Advisory
Impacted products
Vendor Product Version
mattermost mattermost_server *
To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "92B0F8BD-06A1-4B39-95C5-4FB5A195F1C4",
              "versionEndExcluding": "10.11.10",
              "versionStartIncluding": "10.11.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Mattermost versions 10.11.x \u003c= 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 \u0026lt;= 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"
    }
  ],
  "id": "CVE-2026-20796",
  "lastModified": "2026-02-23T15:53:11.073",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 3.1,
          "baseSeverity": "LOW",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 1.4,
        "source": "responsibledisclosure@mattermost.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-02-13T11:16:10.280",
  "references": [
    {
      "source": "responsibledisclosure@mattermost.com",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://mattermost.com/security-updates"
    }
  ],
  "sourceIdentifier": "responsibledisclosure@mattermost.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-367"
        }
      ],
      "source": "responsibledisclosure@mattermost.com",
      "type": "Secondary"
    }
  ]
}


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  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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