Sanitized means to restrict what can be uploaded to a limited expected input, like text and not scripts or commands. A flawed input allows an attacker to inject malicious scripts that can then be used to attack users who visit the site, like the administrator, and do things like download malicious files to their browser or intercept their credentials.

Cross Site Request Forgery is when an attacker tricks a user, like a logged-in administrator, to visit the site and execute various actions.

These vulnerabilities depend on the classic-editor plugin being installed and that the attacker has some kind of user authentication, which makes it harder to exploit.

But these vulnerabilities are still serious and Jetpack recommends users upgraded their plugin to at least version 0.95 of WP Fastest Cache.

WP Fastest Cache version 0.95 was released on October 14, 2021.