GHSA-3X39-62H4-F8J6

Vulnerability from github – Published: 2025-11-27 18:30 – Updated: 2025-12-01 23:56
VLAI?
Summary
Mattermost fails to properly validate OAuth state tokens during OpenID Connect authentication
Details

Mattermost versions 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12, 11.0.x <= 11.0.3 fail to properly validate OAuth state tokens during OpenID Connect authentication which allows an authenticated attacker with team creation privileges to take over a user account via manipulation of authentication data during the OAuth completion flow. This requires email verification to be disabled (default: disabled), OAuth/OpenID Connect to be enabled, and the attacker to control two users in the SSO system with one of them never having logged into Mattermost.

Severity ?
9.9 (Critical)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Show details on source website
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{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/mattermost/mattermost/server/v8"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "8.0.0-20251028000919-d3ed703dc833"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/mattermost/mattermost-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "10.12.0"
            },
            {
              "fixed": "10.12.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/mattermost/mattermost-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "10.11.0"
            },
            {
              "fixed": "10.11.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/mattermost/mattermost-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "10.5.0"
            },
            {
              "fixed": "10.5.13"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/mattermost/mattermost-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "11.0.0"
            },
            {
              "fixed": "11.0.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2025-12419"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-287",
      "CWE-303"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-12-01T23:56:55Z",
    "nvd_published_at": "2025-11-27T16:15:46Z",
    "severity": "CRITICAL"
  },
  "details": "Mattermost versions 10.12.x \u003c= 10.12.1, 10.11.x \u003c= 10.11.4, 10.5.x \u003c= 10.5.12, 11.0.x \u003c= 11.0.3 fail to properly validate OAuth state tokens during OpenID Connect authentication which allows an authenticated attacker with team creation privileges to take over a user account via manipulation of authentication data during the OAuth completion flow. This requires email verification to be disabled (default: disabled), OAuth/OpenID Connect to be enabled, and the attacker to control two users in the SSO system with one of them never having logged into Mattermost.",
  "id": "GHSA-3x39-62h4-f8j6",
  "modified": "2025-12-01T23:56:56Z",
  "published": "2025-11-27T18:30:25Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-12419"
    },
    {
      "type": "WEB",
      "url": "https://github.com/mattermost/mattermost/pull/34296"
    },
    {
      "type": "WEB",
      "url": "https://github.com/mattermost/mattermost/commit/15364790cc277cfaa372693d2d5442b87f70fd42"
    },
    {
      "type": "WEB",
      "url": "https://github.com/mattermost/mattermost/commit/364c2203de00fe0d8424b6b46d6f0eeb02a2539a"
    },
    {
      "type": "WEB",
      "url": "https://github.com/mattermost/mattermost/commit/46b5c436bb3093cc1da3fa2455f93d4c52389eee"
    },
    {
      "type": "WEB",
      "url": "https://github.com/mattermost/mattermost/commit/c3f4818afe46a7084740e809708ae22641c76d8d"
    },
    {
      "type": "WEB",
      "url": "https://github.com/mattermost/mattermost/commit/d3ed703dc8330684952eb8d49a375bac6ea7b0c6"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/mattermost/mattermost"
    },
    {
      "type": "WEB",
      "url": "https://mattermost.com/security-updates"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Mattermost fails to properly validate OAuth state tokens during OpenID Connect authentication"
}


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