CVE-2025-54478: Mattermost Confluence

Medium severity, CVSS 5.3. EPSS: 0.2% chance of exploitation in the next 30 days.

Mattermost Confluence Plugin version <1.5.0 fails to enforce authentication of the user to the Mattermost instance which allows unauthenticated attackers to edit channel subscriptions via API call to the edit channel subscription endpoint.

Affected products

• Mattermost Confluence: before 1.5.0 (fixed in 1.5.0)

Published 2025-08-11. Last modified 2026-06-17.