CVE-2025-13324: Mattermost Server

Low severity, CVSS 3.7. EPSS: 0.2% chance of exploitation in the next 30 days.

Mattermost versions 10.11.x <= 10.11.5, 11.0.x <= 11.0.4, 10.12.x <= 10.12.2 fail to invalidate remote cluster invite tokens when using the legacy (version 1) protocol or when the confirming party does not provide a refreshed token, which allows an attacker who has obtained an invite token to authenticate as the remote cluster and perform limited actions on shared channels even after the invitation has been legitimately confirmed.

Affected products

• Mattermost Mattermost Server: from 10.11.0, before 10.11.6 (fixed in 10.11.6); from 10.12.0, before 10.12.3 (fixed in 10.12.3); from 11.0.0, before 11.0.5 (fixed in 11.0.5)

Published 2025-12-17. Last modified 2026-06-17.