CVE-2025-27538: Mattermost Server

Low severity, CVSS 2.7. EPSS: 0.2% chance of exploitation in the next 30 days.

Mattermost versions 10.5.x <= 10.5.1, 9.11.x <= 9.11.9 fail to enforce MFA checks in PUT /api/v4/users/user-id/mfa when the requesting user differs from the target user ID, which allows users with edit_other_users permission to activate or deactivate MFA for other users, even if those users have not set up MFA.

Affected products

• Mattermost Mattermost Server: from 9.11.0, before 9.11.10 (fixed in 9.11.10); from 10.5.0, before 10.5.2 (fixed in 10.5.2)

Published 2025-04-16. Last modified 2026-06-17.