BuddyPress 14.4.0 contains an insecure direct object reference vulnerability in the messages REST API that allows authenticated attackers to access arbitrary private message threads by supplying a user id parameter in the request. Attackers can pass another user's identifier to the get item permissions check method, which validates the supplied user id instead of the logged-in user and is reused by the update and delete handlers, to read, reply to, or delete any user's private messages.