{"id":"CVE-2026-27659","summary":"CSRF vulnerability in UpdateAccessControlPolicyActiveStatus endpoint","details":"Mattermost versions 11.2.x \u003c= 11.2.2, 10.11.x \u003c= 10.11.10, 11.4.x \u003c= 11.4.0, 11.3.x \u003c= 11.3.1 fail to properly validate CSRF tokens in the /api/v4/access_control_policies/{policy_id}/activate endpoint, which allows an attacker to trick an admin into changing access control policy active status via a crafted request.. Mattermost Advisory ID: MMSA-2026-00578","aliases":["GHSA-rmhw-c3xr-m3xx","GO-2026-5629"],"modified":"2026-07-15T01:49:18.091319206Z","published":"2026-03-25T16:33:32.724Z","database_specific":{"unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"11.2.0"},{"last_affected":"11.2.2"},{"introduced":"10.11.0"},{"last_affected":"10.11.10"},{"introduced":"11.4.0"},{"last_affected":"11.4.0"},{"introduced":"11.3.0"},{"last_affected":"11.3.1"}]}],"cna_assigner":"Mattermost","cwe_ids":["CWE-352"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27659.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27659.json"},{"type":"ADVISORY","url":"https://mattermost.com/security-updates"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-27659"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mattermost/mattermost","events":[{"introduced":"5b955468ea1ea8b56c0fb10feb258a36a767d7bb"},{"fixed":"fddd4a70bcb32eaff394a2fa5399efcd1b2ae251"},{"introduced":"ab7b138824c61fe1fe815243d7e2a914dec49c8b"},{"fixed":"005521aa79666e6960bc3302f6172b810f6bff3a"},{"introduced":"d27a2195068ddfa3ce17cf470f9739e4edb94b83"},{"fixed":"b7d4a1f1f59b645a7598181d33cfc537ea9a6c9c"},{"introduced":"2a1ac98bd3fae587927adf9340ba266c8c02018e"},{"fixed":"84f62bb0c14a45a200af7f4dbe7186915865495f"}],"database_specific":{"source":"CPE_RANGE","cpe":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"10.11.0"},{"fixed":"10.11.11"},{"introduced":"11.2.0"},{"fixed":"11.2.3"},{"introduced":"11.3.0"},{"fixed":"11.3.2"},{"introduced":"11.4.0"},{"fixed":"11.4.1"}]}}],"versions":["v11.3.1","v11.4.0-rc3","v11.4.0","mattermost-redux@11.4.0","@mattermost/types@11.4.0","@mattermost/client@11.4.0","v10.11.11-rc1","v11.3.1-rc1","v10.11.10","v11.2.2","v11.3.0-rc4","v11.3.0-rc3","v11.3.0","mattermost-redux@11.3.0","@mattermost/types@11.3.0","@mattermost/client@11.3.0","v10.11.9","v11.2.1","v11.2.1-rc1","v11.2.0","v10.11.9-rc1","v10.11.8","v10.11.7","v10.11.6","v10.11.5","v10.11.4-rc3","v10.11.4","v10.11.4-rc2","v10.11.4-rc1","v10.11.3","v10.11.2-rc2","v10.11.2","v10.11.2-rc1","v10.11.1","v10.11.1-rc1","v10.11.0-rc3","v10.11.0","mattermost-redux@10.11.0","@mattermost/types@10.11.0","@mattermost/client@10.11.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-27659.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N"}]}