The Royal Elementor Addons and Templates plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 1.3.87. This is due to missing or incorrect nonce validation on the add_to_compare function. This makes it possible for unauthenticated attackers to add items to user compare lists via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.