Grav API Plugin is a RESTful API for Grav CMS that provides full headless access to your site's content, media, configuration, users, and system management. Prior to 1.0.0-beta.15, an insecure direct object reference and logic flaw in the Grav API plugin (UsersController::update) allows any authenticated user with basic API access (api.access) to modify their own permission configuration. An attacker can exploit this to escalate their privileges to Super Administrator (admin.super and api.super)