ProfileGrid < 5.9.9.7 - Subscriber+ Cross-User Private Message Thread Deletion and Tampering via Missing Authorization

The ProfileGrid WordPress plugin before 5.9.9.7 does not perform any authorization or ownership check on some of its private-message thread actions, allowing authenticated users with Subscriber-level access and above to soft-delete, tamper with the metadata of, and mark as read other users' private message threads.