{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "10.11.0"
              },
              {
                "fixed": "10.11.12"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "5b955468ea1ea8b56c0fb10feb258a36a767d7bb"
            },
            {
              "fixed": "e1a78d1e9111eb77008014c8fec345708c74e756"
            }
          ],
          "repo": "https://github.com/mattermost/mattermost",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Mattermost",
    "cwe_ids": [
      "CWE-754"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/3xxx/CVE-2026-3109.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "last_affected": "10.11.11"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "Mattermost Plugins versions \u003c=11.4 10.11.11.0 fail to validate webhook request timestamps which allows an attacker to corrupt Zoom meeting state in Mattermost via replayed webhook requests. Mattermost Advisory ID: MMSA-2026-00584",
  "id": "CVE-2026-3109",
  "modified": "2026-07-15T01:49:21.232037428Z",
  "published": "2026-03-26T16:28:07.362Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/3xxx/CVE-2026-3109.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://mattermost.com/security-updates"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-3109"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Missing timestamp validation in Zoom webhook handler"
}