GHSA-3c9r-7f29-qp32MediumCVSS 5.4

Mattermost fails to properly validate login method restrictions

Published
February 16, 2026
Last Modified
February 19, 2026

🔗 CVE IDs covered (1)

CVE-2026-0999 →

📋 Description

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 products5

  • go/github.com/mattermost/mattermost/server/v8:< 8.0.0-20251212052346-61651b0df7ea
  • go/github.com/mattermost/mattermost-server:>= 11.1.0, < 11.1.3
  • go/github.com/mattermost/mattermost-server:>= 10.11.0, < 10.11.10
  • go/github.com/mattermost/mattermost-server:>= 11.2.0, < 11.2.2
  • go/github.com/mattermost/mattermost-server:< 5.3.2-0.20251212052346-61651b0df7ea

🔗 References (4)