CVE-2026-12284

Mattermost Desktop App versions

CVE-2026-12284: Origin Validation Error

Mattermost Desktop App versions =6.2 6.2.2.0 fails to validate the IPC sender in the leaveCall handler which allows a malicious or compromised Mattermost server or a user with script access to a connected server view to disconnect an active call belonging to a different connected server via the...