CVE-2024-40886: Mattermost

High severity, CVSS 8.8. EPSS: 0.2% chance of exploitation in the next 30 days.

Mattermost versions 9.9.x <= 9.9.1, 9.5.x <= 9.5.7, 9.10.x <= 9.10.0, 9.8.x <= 9.8.2 fail to sanitize user inputs in the frontend that are used for redirection which allows for a one-click client-side path traversal that is leading to CSRF in User Management page of the system console.

Affected products

• Mattermost Mattermost: from 9.5.0, before 9.5.8 (fixed in 9.5.8); from 9.8.0, before 9.8.3 (fixed in 9.8.3); from 9.9.0, before 9.9.2 (fixed in 9.9.2); from 9.10.0, before 9.10.1 (fixed in 9.10.1)

Published 2024-08-22. Last modified 2026-06-17.