The WordPress Mega Menu – QuadMenu plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 3.2.0. This is due to missing or incorrect nonce validation on the ajax_dismiss_notice() function. This makes it possible for unauthenticated attackers to update any user meta to a value of one, including wp_capabilities which could result in a privilege deescalation of an administrator, via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.