FreeScout: Thread Deletion Bypasses Mailbox Access Revocation

FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to 1.8.221, FreeScout allows a non-admin user to permanently delete an internal note (private thread) from any conversation, even after that user's access to the mailbox containing the conversation has been revoked. The ThreadPolicy::delete authorization policy does not verify mailbox membership, so a former team member retains destructive write access to notes they created. This vulnerability is fixed in 1.8.221.