The Hashthemes Demo Importer Plugin <= 1.1.1 for WordPress contained several AJAX functions which relied on a nonce which was visible to all logged-in users for access control, allowing them to execute a function that truncated nearly all database tables and removed the contents of wp-content/uploads.
https://www.wordfence.com/blog/2021/10/site-deletion-vulnerability-in-hashthemes-plugin/