The WCFM Marketplace plugin for WordPress is vulnerable to unauthorized modification and access of data in versions up to, and including, 3.4.11 due to missing capability checks on various AJAX actions. This makes it possible for authenticated attackers, with minimal permissions such as subscribers, to perform a wide variety of actions such as modifying shipping method details, modifying products, deleting arbitrary posts, and privilege escalation (via the wp_ajax_wcfm_vendor_store_online AJAX action).