The App Builder – Create Native Android & iOS Apps On The Flight plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 5.5.10. This is due to the verify_role() function in AuthTrails.php explicitly whitelisting the wcfm_vendor role alongside subscriber and customer, and assigning it directly via wp_insert_user() without integrating with WCFM Marketplace's vendor approval workflow. This makes it possible for unauthenticated attackers to register an account with the wcfm_vendor role by supplying the role parameter in the /wp-json/app-builder/v1/register REST API endpoint, bypassing the standard WCFM vendor approval process and immediately gaining vendor-level privileges (product management, order access, store management) on sites where WCFM Marketplace is active.