CVE-2025-49810: Mattermost Server

Medium severity, CVSS 4.3. EPSS: 0.2% chance of exploitation in the next 30 days.

Mattermost versions 10.5.x <= 10.5.8 fail to validate access controls at time of access which allows user to read a thread via AI posts

Affected products

• Mattermost Mattermost Server: from 10.5.0, before 10.5.9 (fixed in 10.5.9)

Published 2025-08-21. Last modified 2026-06-17.