{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
                "range": [
                  {
                    "introduced": "11.7.0"
                  },
                  {
                    "fixed": "11.7.10"
                  }
                ],
                "source": "CPE_RANGE"
              },
              {
                "cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
                "range": [
                  {
                    "introduced": "11.9.0"
                  },
                  {
                    "fixed": "11.9.2"
                  }
                ],
                "source": "CPE_RANGE"
              },
              {
                "cpe": "cpe:2.3:a:mattermost:mattermost_server:11.10.0:*:*:*:*:*:*:*",
                "range": [
                  {
                    "introduced": "11.10.0"
                  },
                  {
                    "last_affected": "11.10.0"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          },
          "events": [
            {
              "introduced": "a9e574a82633915f22071f0d7ca2b006f249ec2a"
            },
            {
              "fixed": "dee04aa1179b6e3b6a7aca67b95ad0e7efefaa80"
            },
            {
              "introduced": "583461af10fc9b2aef2871c722fc4376db695832"
            },
            {
              "fixed": "8ed7691c22159afec427468b8a866aeeaf59a12c"
            },
            {
              "introduced": "7f5bffb8cf3977db8237ce10158fa22aa0d2504f"
            },
            {
              "last_affected": "7f5bffb8cf3977db8237ce10158fa22aa0d2504f"
            }
          ],
          "repo": "https://github.com/mattermost/mattermost",
          "type": "GIT"
        }
      ],
      "versions": [
        "11.10.0"
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Mattermost",
    "cwe_ids": [
      "CWE-862"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/18xxx/CVE-2026-18795.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "range": [
              {
                "introduced": "11.10.0"
              },
              {
                "last_affected": "11.10.0"
              }
            ],
            "source": "AFFECTED_FIELD",
            "strategy": "StandaloneSingleVersion"
          }
        ]
      },
      {
        "extracted_events": [
          {
            "range": [
              {
                "introduced": "11.7.0"
              },
              {
                "last_affected": "11.7.9"
              },
              {
                "introduced": "11.9.0"
              },
              {
                "last_affected": "11.9.1"
              },
              {
                "introduced": "11.8.0"
              },
              {
                "last_affected": "11.8.5"
              }
            ],
            "source": "AFFECTED_FIELD",
            "strategy": "StandardRange"
          }
        ]
      }
    ]
  },
  "details": "Mattermost versions 11.10.x \u003c= 11.10.0, 11.7.x \u003c= 11.7.9, 11.9.x \u003c= 11.9.1, 11.8.x \u003c= 11.8.5 fail to enforce DM/GM check on server side which allows an authenticated user to quarantine a post belonging to DM or GM via direct API call.. Mattermost Advisory ID: MMSA-2026-00756",
  "id": "CVE-2026-18795",
  "modified": "2026-10-31T02:30:20.952501086Z",
  "published": "2026-10-16T07:01:22.549Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/18xxx/CVE-2026-18795.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://mattermost.com/security-updates"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-18795"
    }
  ],
  "schema_version": "1.9.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Missing server side validation allowed user to quarantine a DM and GM post"
}