{"id":"CVE-2026-82920","summary":"Mattermost ABAC parent policy bypass via policy update endpoint","details":"Mattermost versions 11.9.x \u003c= 11.9.0, 11.8.x \u003c= 11.8.4, 11.7.x \u003c= 11.7.7 fail to enforce authorization boundaries on the access control policy update endpoint which allows a channel or team administrator to detach a system-assigned ABAC parent policy via a crafted PUT /api/v4/access_control_policies request with an empty imports list.. Mattermost Advisory ID: MMSA-2026-00724","modified":"2026-10-09T02:49:30.123651279Z","published":"2026-09-14T13:59:01.993Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/82xxx/CVE-2026-82920.json","unresolved_ranges":[{"extracted_events":[{"introduced":"11.8.0"},{"last_affected":"11.8.4"},{"introduced":"11.7.0"},{"last_affected":"11.7.7"},{"introduced":"11.9.0"},{"last_affected":"11.9.0"}],"source":"AFFECTED_FIELD"}],"cna_assigner":"Mattermost","cwe_ids":["CWE-863"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/82xxx/CVE-2026-82920.json"},{"type":"ADVISORY","url":"https://mattermost.com/security-updates"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-82920"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mattermost/mattermost","events":[{"introduced":"a9e574a82633915f22071f0d7ca2b006f249ec2a"},{"fixed":"d42004bb3046de3ed176938a34b1a70c1c3d9421"},{"introduced":"e8bd2b8a871cbeff6943bead62328478118188df"},{"fixed":"d9c17e42b19c27dfac0ebe6840d954a41e626890"},{"introduced":"583461af10fc9b2aef2871c722fc4376db695832"},{"fixed":"1f738d345805168964a55e5860aac9c747dceb78"}],"database_specific":{"extracted_events":[{"introduced":"11.7.0"},{"fixed":"11.7.8"},{"introduced":"11.8.0"},{"fixed":"11.8.5"},{"introduced":"11.9.0"},{"fixed":"11.9.1"}],"source":"CPE_RANGE","cpe":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*"}}],"versions":["v11.8.4","v11.7.7","v11.9.0","mattermost-redux@11.9.0","@mattermost/types@11.9.0","@mattermost/shared@11.9.0","@mattermost/client@11.9.0","v11.8.3","v11.7.6","v11.8.2","v11.7.5-rc1","v11.7.5","v11.8.1","v11.7.4","v11.7.3","v11.8.0-rc5","v11.8.0","mattermost-redux@11.8.0","@mattermost/types@11.8.0","@mattermost/shared@11.8.0","@mattermost/client@11.8.0","v11.7.2","v11.7.1","v11.7.0","mattermost-redux@11.7.0","@mattermost/types@11.7.0","@mattermost/shared@11.7.0","@mattermost/client@11.7.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-82920.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N"}]}