{"id":"CVE-2026-0999","details":"Mattermost versions 11.1.x \u003c= 11.1.2, 10.11.x \u003c= 10.11.9, 11.2.x \u003c= 11.2.1 fail to properly validate login method restrictions which allows an authenticated user to bypass SSO-only login requirements via userID-based authentication. Mattermost Advisory ID: MMSA-2025-00548","aliases":["GHSA-3c9r-7f29-qp32","GO-2026-4520"],"modified":"2026-03-13T04:08:42.005554Z","published":"2026-02-16T10:16:08.140Z","related":["SUSE-SU-2026:0757-1"],"references":[{"type":"ADVISORY","url":"https://mattermost.com/security-updates"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mattermost/mattermost-server","events":[{"introduced":"5b955468ea1ea8b56c0fb10feb258a36a767d7bb"},{"fixed":"ba27ba1f8cb1ffe2b1a79dc3d15a3ffa7de12fd7"},{"introduced":"e62f350cd7a896c45a0e025f44cb8915f5597854"},{"fixed":"7d0e4261dd4bc45162be3183ac19241f43a3f994"},{"introduced":"ab7b138824c61fe1fe815243d7e2a914dec49c8b"},{"fixed":"cfbe9d9254d4903777fab5957924d260cb5b74ff"}],"database_specific":{"versions":[{"introduced":"10.11.0"},{"fixed":"10.11.10"},{"introduced":"11.1.0"},{"fixed":"11.1.3"},{"introduced":"11.2.0"},{"fixed":"11.2.2"}]}}],"versions":["@mattermost/client@10.11.0","@mattermost/client@11.1.0","@mattermost/types@10.11.0","@mattermost/types@11.1.0","mattermost-redux@10.11.0","mattermost-redux@11.1.0","v10.11.0","v10.11.0-rc3","v10.11.1","v10.11.1-rc1","v10.11.2","v10.11.2-rc1","v10.11.2-rc2","v10.11.3","v10.11.4","v10.11.4-rc1","v10.11.4-rc2","v10.11.4-rc3","v10.11.5","v10.11.6","v10.11.7","v10.11.8","v10.11.9","v10.11.9-rc1","v11.1.0","v11.1.0-rc4","v11.1.1","v11.1.1-rc1","v11.1.1-rc2","v11.1.2","v11.1.2-rc1","v11.2.0","v11.2.1","v11.2.1-rc1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-0999.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N"}]}