{"id":"CVE-2025-11777","summary":"Cross-team channel membership access","details":"Mattermost versions 10.11.x \u003c= 10.11.3, 10.5.x \u003c= 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint","aliases":["GHSA-mqcj-8c2g-h97q","GO-2025-4122"],"modified":"2026-10-24T10:31:42.454777056Z","published":"2025-11-13T17:32:03.975Z","related":["SUSE-SU-2026:0037-1","openSUSE-SU-2026:21483-1"],"database_specific":{"cna_assigner":"Mattermost","cwe_ids":["CWE-863"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/11xxx/CVE-2025-11777.json","unresolved_ranges":[{"extracted_events":[{"range":[{"introduced":"10.11.0"},{"last_affected":"10.11.3"},{"introduced":"10.5.0"},{"last_affected":"10.5.11"}],"source":"AFFECTED_FIELD","strategy":"StandardRange"}]}]},"references":[{"type":"WEB","url":"https://mattermost.com/security-updates"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/11xxx/CVE-2025-11777.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-11777"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mattermost/mattermost","events":[{"introduced":"58bd34fd34cbd7d3da777d627b6cffdf8a532930"},{"fixed":"9fa25cd55b43d735a39c6925d7e0021697ae049d"},{"introduced":"5b955468ea1ea8b56c0fb10feb258a36a767d7bb"},{"fixed":"83a5be3f9ed65d8457ab8cca853826d0c8425a8b"}],"database_specific":{"extracted_events":[{"range":[{"introduced":"10.5.0"},{"fixed":"10.5.12"}],"source":"CPE_RANGE","cpe":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*"},{"cpe":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*","range":[{"introduced":"10.11.0"},{"fixed":"10.11.4"}],"source":"CPE_RANGE"}]}}],"versions":["v10.11.4-rc2","v10.5.12-rc1","v10.11.4-rc1","v10.11.3","v10.5.11","v10.11.2-rc2","v10.11.2","v10.5.11-rc1","v10.11.2-rc1","v10.5.10","v10.11.1","v10.5.10-rc2","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","v10.5.10-rc1","v10.5.9","v10.5.9-rc4","v10.5.9-rc3","v10.5.9-rc2","v10.5.9-rc1","v10.5.8","v10.5.8-rc1","v10.5.7","v10.5.6-rc1","v10.5.6","v10.5.5","v10.5.5-rc1","v10.5.4-rc2","v10.5.4","v10.5.4-rc1","v10.5.3","v10.5.3-rc1","v10.5.2","v10.5.1","v10.5.1-rc2","v10.5.1-rc1","v10.5.0-rc6","v10.5.0","@mattermost/types@10.5.0","@mattermost/client@10.5.0"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-11777.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N"}]}