{"schema_version":"1.9.0","id":"CVE-2025-10545","published":"2025-10-16T08:24:25.928Z","modified":"2026-08-12T03:51:19.256149108Z","aliases":["GHSA-424h-xj87-m937","GO-2025-4030"],"related":["openSUSE-SU-2025:15710-1","openSUSE-SU-2026:21483-1"],"summary":"Guest user can add unauthorized team users to private channels","details":"Mattermost versions 10.5.x <= 10.5.10, 10.11.x <= 10.11.2 fail to properly validate guest user permissions when adding channel members which allows guest users to add any team members to their private channels via the `/api/v4/channels/{channel_id}/members` endpoint","affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mattermost/mattermost","events":[{"introduced":"58bd34fd34cbd7d3da777d627b6cffdf8a532930"},{"fixed":"bb822798f39a7f8c58b74c603f71ffb8a8f7a9be"},{"introduced":"5b955468ea1ea8b56c0fb10feb258a36a767d7bb"},{"fixed":"f1f6719f38e167657caa46f45086ee3d3bf7e6d5"}],"database_specific":{"cpe":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"10.5.0"},{"fixed":"10.5.11"},{"introduced":"10.11.0"},{"fixed":"10.11.3"}],"source":"CPE_RANGE"}}],"versions":["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/cve-osv-conversion/osv-output/CVE-2025-10545.json"}}],"references":[{"type":"WEB","url":"https://mattermost.com/security-updates"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/10xxx/CVE-2025-10545.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-10545"}],"database_specific":{"cna_assigner":"Mattermost","cwe_ids":["CWE-863"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/10xxx/CVE-2025-10545.json","unresolved_ranges":[{"extracted_events":[{"introduced":"10.5.0"},{"last_affected":"10.5.10"},{"introduced":"10.11.0"},{"last_affected":"10.11.2"}],"source":"AFFECTED_FIELD"}]},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N"}]}