CVE-2025-53857: Mattermost Confluence

Low severity, CVSS 3.7. EPSS: 0.2% chance of exploitation in the next 30 days.

Mattermost Confluence Plugin version <1.5.0 fails to check the access of the user to the channel which allows attackers to get channel subscription details without proper access to the channel via API call to the GET autocomplete/GetChannelSubscriptions endpoint.

Affected products

• Mattermost Confluence: before 1.5.0 (fixed in 1.5.0)

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