{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "10.11.0"
              },
              {
                "fixed": "10.11.20"
              },
              {
                "introduced": "11.6.0"
              },
              {
                "fixed": "11.6.5"
              },
              {
                "introduced": "11.7.0"
              },
              {
                "fixed": "11.7.3"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "5b955468ea1ea8b56c0fb10feb258a36a767d7bb"
            },
            {
              "fixed": "31b97d9ee1e020ca63f2169e4daab4aa0519a727"
            },
            {
              "introduced": "d4f4e78835e86e2e76f76bfe797623076f5c9835"
            },
            {
              "fixed": "b94397a68c6129bb904dcb0ab7643b188f2717b0"
            },
            {
              "introduced": "a9e574a82633915f22071f0d7ca2b006f249ec2a"
            },
            {
              "fixed": "28b63b15f73e0ed02d0da0018e06d88c47a77c48"
            }
          ],
          "repo": "https://github.com/mattermost/mattermost",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Mattermost",
    "cwe_ids": [
      "CWE-305"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/9xxx/CVE-2026-9571.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "11.7.0"
          },
          {
            "last_affected": "11.7.2"
          },
          {
            "introduced": "11.6.0"
          },
          {
            "last_affected": "11.6.4"
          },
          {
            "introduced": "10.11.0"
          },
          {
            "last_affected": "10.11.19"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "Mattermost versions 11.7.x \u003c= 11.7.2, 11.6.x \u003c= 11.6.4, 10.11.x \u003c= 10.11.19 fail to invalidate OAuth refresh tokens upon user account deactivation, which allows a deactivated user or an attacker in possession of a valid refresh token to obtain new functional access tokens via the OAuth refresh token grant endpoint.. Mattermost Advisory ID: MMSA-2026-00680",
  "id": "CVE-2026-9571",
  "modified": "2026-07-16T03:31:17.510835578Z",
  "published": "2026-07-13T07:50:55.793Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/9xxx/CVE-2026-9571.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://mattermost.com/security-updates"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-9571"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Deactivated user accounts can continue to obtain valid OAuth access tokens via refresh token grant in Mattermost"
}