The Seraphinite Accelerator plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 2.27.21. This is due to missing or incorrect nonce validation on the 'OnAdminApi_CacheOpBegin' function. This makes it possible for unauthenticated attackers to perform several administrative actions, including deleting the cache, via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.