CVE-2021-4416
The wp-mpdf plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 3.5.1. This is due to missing or incorrect nonce validation on the mpdf_admin_savepost() function. This makes it possible for unauthenticated attackers to save post data via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
Source: CVE-2021-4416