{"id":"CVE-2026-10527","aliases":["EUVD-2026-60192","GHSA-ghq9-4rcg-jvc2"],"status":"published","title":"Boards plugin retains Board Admin rights for users demoted to System Guest","description":"Mattermost versions 11.7.x \u003c= 11.7.6, 10.11.x \u003c= 10.11.21, 11.8.x \u003c= 11.8.3 fails to reconcile SchemeAdmin flags with a user's current role which allows a user demoted to System Guest to retain Board Admin privileges and perform admin-only operations via the Boards REST API or UI.. Mattermost Advisory ID: MMSA-2026-00691","severity":{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.0026,"percentile":0.17895,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-863"],"published":"2026-08-17T14:37:46Z","modified":"2026-10-28T02:30:22Z","products":[{"vendor":"mattermost","product":"mattermost"},{"vendor":"mattermost","product":"mattermost_server"}],"references":[{"url":"https://mattermost.com/security-updates","tags":["vendor-advisory","Vendor Advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-10527","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-ghq9-4rcg-jvc2"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/10xxx/CVE-2026-10527.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-10527","title":"Boards plugin retains Board Admin rights for users demoted to System Guest","description":"Mattermost versions 11.7.x \u003c= 11.7.6, 10.11.x \u003c= 10.11.21, 11.8.x \u003c= 11.8.3 fails to reconcile SchemeAdmin flags with a user's current role which allows a user demoted to System Guest to retain Board Admin privileges and perform admin-only operations via the Boards REST API or UI.. Mattermost Advisory ID: MMSA-2026-00691","status":"published","published":"2026-08-17T14:37:46.253Z","modified":"2026-08-17T15:25:25.134Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-863"],"updated_at":"2026-11-02T13:40:01.309549Z"}],"euvd":[{"id":"EUVD-2026-60192","description":"Mattermost versions 11.7.x \u003c= 11.7.6, 10.11.x \u003c= 10.11.21, 11.8.x \u003c= 11.8.3 fails to reconcile SchemeAdmin flags with a user's current role which allows a user demoted to System Guest to retain Board Admin privileges and perform admin-only operations via the Boards REST API or UI.. Mattermost Advisory ID: MMSA-2026-00691","status":"published","published":"2026-08-17T14:37:46Z","modified":"2026-08-17T15:25:25Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L","level":"medium"}],"updated_at":"2026-11-02T18:01:49.335011Z"}],"ghsa":[{"id":"GHSA-ghq9-4rcg-jvc2","title":"Mattermost versions 11.7.x \u003c= 11.7.6, 10.11.x \u003c= 10.11.21, 11.8.x \u003c= 11.8.3 fails to reconcile...","description":"Mattermost versions 11.7.x \u003c= 11.7.6, 10.11.x \u003c= 10.11.21, 11.8.x \u003c= 11.8.3 fails to reconcile SchemeAdmin flags with a user's current role which allows a user demoted to System Guest to retain Board Admin privileges and perform admin-only operations via the Boards REST API or UI.. Mattermost Advisory ID: MMSA-2026-00691","status":"published","published":"2026-08-17T15:30:40Z","modified":"2026-08-17T15:30:41Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L","level":"medium"}],"cwes":["CWE-863"],"updated_at":"2026-11-02T15:10:34.652326Z"}],"nvd":[{"id":"CVE-2026-10527","description":"Mattermost versions 11.7.x \u003c= 11.7.6, 10.11.x \u003c= 10.11.21, 11.8.x \u003c= 11.8.3 fails to reconcile SchemeAdmin flags with a user's current role which allows a user demoted to System Guest to retain Board Admin privileges and perform admin-only operations via the Boards REST API or UI.. Mattermost Advisory ID: MMSA-2026-00691","status":"published","published":"2026-08-17T15:16:53.087Z","modified":"2026-08-18T20:21:57.433Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L","level":"medium","assessor":"secondary"}],"cwes":["CWE-863"],"updated_at":"2026-11-02T14:12:38.647684Z"}],"osv":[{"id":"CVE-2026-10527","title":"Boards plugin retains Board Admin rights for users demoted to System Guest","description":"Mattermost versions 11.7.x \u003c= 11.7.6, 10.11.x \u003c= 10.11.21, 11.8.x \u003c= 11.8.3 fails to reconcile SchemeAdmin flags with a user's current role which allows a user demoted to System Guest to retain Board Admin privileges and perform admin-only operations via the Boards REST API or UI.. Mattermost Advisory ID: MMSA-2026-00691","status":"published","published":"2026-08-17T14:37:46.253Z","modified":"2026-10-28T02:30:22.342950532Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L","level":"medium"}],"cwes":["CWE-863"],"updated_at":"2026-11-02T15:44:54.583213Z"}]}}