{"id":"CVE-2025-10545","aliases":["GHSA-424h-xj87-m937","GO-2025-4030"],"url":"https://o3.security/vulnerability/CVE-2025-10545","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","published":"2025-10-16T08:24:25.928Z","modified":"2026-07-31T18:29:59.754141140Z","cvss":{"score":3.1,"severity":"LOW","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/mattermost/mattermost/server/v8","fixedVersion":"8.0.0-20250820115038-ff30b84049f0"},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","fixedVersion":"10.5.11"},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","fixedVersion":"10.11.3"}],"fix":null,"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"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-31T18:29:59.754141140Z"}}