BuddyPress 14.4.0 Private Message IDOR via REST API user_id Parameter

CVE-2026-53673

What is CVE-2026-53673?

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.

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