WPQA < 5.2 - Subscriber+ Private Message Disclosure via IDOR

The WPQA Builder Plugin WordPress plugin before 5.2, used as a companion plugin for the Discy and Himer , does not validate that the message_id of the wpqa_message_view ajax action belongs to the requesting user, leading to any user being able to read messages for any other users via a Insecure Direct Object Reference (IDOR) vulnerability.