The Wishlist Member plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the 'WishListMember3_Hooks::generate_api_key' function in all versions up to, and including, 3.30.1. This makes it possible for authenticated attackers, with Subscriber-level access and above, to update the REST API Secret Key, which can be used to create a new membership level assigned the administrator WordPress role, and register an arbitrary administrator-level user account, resulting in complete site takeover.