The 6Storage Rentals plugin for WordPress is vulnerable to Authorization Bypass Through User-Controlled Key in all versions up to and including 2.22.0 via the `userId` parameter of the `six_storage_get_user_info` and `six_storage_update_profile` AJAX actions. This is due to the `six_storage_getUserInfo()` and `six_storage_updateProfile()` functions being registered on `wp_ajax_nopriv_*` hooks and accepting a tenant identifier directly from `$_POST['userId']` without performing any ownership verification, session binding, or nonce validation to confirm the requester has a legitimate relationship to the supplied ID. This makes it possible for unauthenticated attackers to read and modify arbitrary tenants' profile data — including name, email address, phone number, physical address, and SSN — by supplying an enumerated `userId` value in a crafted request to either handler.