CVE-2025-25279: Mattermost Server

High severity, CVSS 7.5. EPSS: 24.2% chance of exploitation in the next 30 days.

Mattermost versions 10.4.x <= 10.4.1, 9.11.x <= 9.11.7, 10.3.x <= 10.3.2, 10.2.x <= 10.2.2 fail to properly validate board blocks when importing boards which allows an attacker could read any arbitrary file on the system via importing and exporting a specially crafted import archive in Boards.

Affected products

• Mattermost Mattermost Server: from 9.11.0, before 9.11.8 (fixed in 9.11.8); from 10.2.0, before 10.2.3 (fixed in 10.2.3); from 10.3.0, before 10.3.3 (fixed in 10.3.3); from 10.4.0, before 10.4.2 (fixed in 10.4.2)

Published 2025-02-24. Last modified 2026-06-17.