FreeScout is a self-hosted help desk and shared mailbox application. Prior to version 1.8.226, the  polycast/receive  endpoint fails to escape SQL LIKE wildcards in supplied channel names, while channel authorization applies only to names with specific prefixes. An unauthenticated attacker with a guest session and valid CSRF token can submit a wildcard channel name to retrieve matching notification events intended for other users. Notification payload generation lacks a corresponding access check, exposing conversation message content, identifiers, URLs, and notification HTML across users and mailboxes. This issue is fixed in version 1.8.226.