CVE-2025-14350: Mattermost Server

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

Mattermost versions 11.1.x <= 11.1.2, 10.11.x <= 10.11.9, 11.2.x <= 11.2.1 fail to properly validate team membership when processing channel mentions which allows authenticated users to determine the existence of teams and their URL names via posting channel shortlinks and observing the channel_mentions property in the API response. Mattermost Advisory ID: MMSA-2025-00563

Affected products

• Mattermost Mattermost Server: from 10.11.0, before 10.11.10 (fixed in 10.11.10); from 11.1.0, before 11.1.3 (fixed in 11.1.3); from 11.2.0, before 11.2.2 (fixed in 11.2.2)

Published 2026-02-16. Last modified 2026-06-17.