Improper Access Control in Mattermost Google Drive Plugin File Creation Endpoint

{
  "id": "6654d322bd78048fce92398380dae65a146768ccb475db6e8557abef0504fe96",
  "url": "https://osv.dev/vulnerability/CVE-2026-2299",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Improper Access Control in Mattermost Google Drive Plugin File Creation Endpoint",
    "summary": "The Mattermost Google Drive plugin before version 1.1.0 fails to validate channel membership in the file creation endpoint, allowing authenticated users with a connected Google account to share Google Drive files to unauthorized private channels and disclose private channel membership.",
    "evidence": "osv:CVE-2026-2299",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-2299",
      "aliases": [
        "CVE-2026-2299"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/mattermost/mattermost-plugin-google-drive",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "c8e4c79dde1c785d26e2b2eb414f0ae682d63be8"
                },
                {
                  "introduced": "2fe647c1bc421a3b6e14ee56f8132e69289a620a"
                },
                {
                  "last_affected": "c8e4c79dde1c785d26e2b2eb414f0ae682d63be8"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:mattermost:google_drive:*:*:*:*:*:mattermost:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.1.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:mattermost:google_drive:1.1.0:rc1:*:*:*:mattermost:*:*",
                    "range": [
                      {
                        "introduced": "1.1.0-rc1"
                      },
                      {
                        "last_affected": "1.1.0-rc1"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "cpe": "cpe:2.3:a:mattermost:google_drive:1.1.0:rc2:*:*:*:mattermost:*:*",
                    "range": [
                      {
                        "introduced": "1.1.0-rc2"
                      },
                      {
                        "last_affected": "1.1.0-rc2"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "range": [
                      {
                        "fixed": "c8e4c79dde1c785d26e2b2eb414f0ae682d63be8"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v1.1.0"
                  }
                ]
              }
            }
          ],
          "versions": [
            "1.1.0-rc1",
            "1.1.0-rc2",
            "v1.1.0-rc1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-2299.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:35.600338678Z",
      "provider": "osv",
      "references": [
        "https://github.com/mattermost/mattermost-plugin-google-drive/releases/tag/v1.1.0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/2xxx/CVE-2026-2299.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-2299",
        "https://github.com/mattermost/mattermost-plugin-google-drive"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-862"
        ],
        "cna_assigner": "Mattermost",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/2xxx/CVE-2026-2299.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-2299",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 503020,
  "published_at": "2026-06-25T18:55:11.905+00:00"
}