The Blog2Social: Social Media Auto Post & Scheduler plugin for WordPress is vulnerable to authorization bypass through user-controlled key in all versions up to, and including, 8.8.3. This is due to the plugin's AJAX handlers failing to validate that the user-supplied 'b2s_id' parameter belongs to the current user before performing UPDATE and DELETE operations. This makes it possible for authenticated attackers, with Subscriber-level access and above, to modify, reschedule, or delete other users' scheduled social media posts.