Popup Box AYS Pro < 5.5.0 - Admin+ Stored Cross-Site Scripting (XSS) via CSRF

The Popup Box WordPress plugin before 5.5.0 does not properly validate nonces in the add_or_edit_popupbox() function before saving popup data, allowing unauthenticated attackers to perform Cross-Site Request Forgery attacks. When an authenticated admin visits a malicious page, the attacker can create or modify popups with arbitrary JavaScript that executes in the admin panel and frontend.