cbcvebase.
CVE-2026-0999
published 2026-02-16

CVE-2026-0999: Mattermost versions 11.1.x <= 11.1.2, 10.11.x <= 10.11.9, 11.2.x <= 11.2.1 fail to properly validate login method restrictions which allows an authenticated…

medium4.3CVSS 3.1
AVNACLPRLUINSUCNILAN
Mattermost versions 11.1.x <= 11.1.2, 10.11.x <= 10.11.9, 11.2.x <= 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

Affected

14 ranges
VendorProductVersion rangeFixed in
github.commattermost_mattermost-server>= 0 < 5.3.2-0.20251212052346-61651b0df7ea5.3.2-0.20251212052346-61651b0df7ea
github.commattermost_mattermost-server>= 10.11.0
github.commattermost_mattermost-server>= 10.11.0+incompatible
github.commattermost_mattermost-server>= 11.1.0
github.commattermost_mattermost-server>= 11.1.0+incompatible
github.commattermost_mattermost-server>= 11.2.0
github.commattermost_mattermost-server>= 11.2.0+incompatible
github.commattermost_mattermost_server_v8>= 0 < 8.0.0-20251212052346-61651b0df7ea8.0.0-20251212052346-61651b0df7ea
mattermostmattermost10.11.0 – 10.11.9
mattermostmattermost11.1.0 – 11.1.2
mattermostmattermost11.2.0 – 11.2.1
mattermostmattermost_server>= 10.11.0 < 10.11.1010.11.10
mattermostmattermost_server>= 11.1.0 < 11.1.311.1.3
mattermostmattermost_server>= 11.2.0 < 11.2.211.2.2