ProfileGrid – User Profiles, Groups and Communities <= 5.9.4.2 - Insecure Direct Object Reference to Authenticated (Subscriber+) Private Messages Disclosure

The ProfileGrid – User Profiles, Groups and Communities plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 5.9.4.2 via the pm_messenger_show_messages function due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with Subscriber-level access and above, to read private conversations of other users.