{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "10.11.0"
              },
              {
                "fixed": "10.11.21"
              },
              {
                "introduced": "11.7.0"
              },
              {
                "fixed": "11.7.6"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "5b955468ea1ea8b56c0fb10feb258a36a767d7bb"
            },
            {
              "fixed": "638007314e9dde1575d3caa167e1067b1c577204"
            },
            {
              "introduced": "a9e574a82633915f22071f0d7ca2b006f249ec2a"
            },
            {
              "fixed": "3e198e4d5518c09836ea4c8e7ac7201c83aab67b"
            }
          ],
          "repo": "https://github.com/mattermost/mattermost",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Mattermost",
    "cwe_ids": [
      "CWE-459"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/9xxx/CVE-2026-9693.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "10.11.0"
          },
          {
            "last_affected": "10.11.20"
          },
          {
            "introduced": "11.7.0"
          },
          {
            "last_affected": "11.7.5"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "Mattermost versions 10.11.x \u003c= 10.11.20, 11.7.x \u003c= 11.7.5 Mattermost fails to remove thread membership records when a user is removed from or leaves a team, which allows a previously removed user who is later re-invited to the team to view private channel thread root post content and metadata via the team threads API.. Mattermost Advisory ID: MMSA-2026-00682",
  "id": "CVE-2026-9693",
  "modified": "2026-08-21T03:30:41.338576217Z",
  "published": "2026-08-17T22:07:12.958Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/9xxx/CVE-2026-9693.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://mattermost.com/security-updates"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-9693"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Mattermost thread memberships persist after team removal, exposing private channel thread metadata on re-invite"
}