Anti-Spam by CleanTalk < 6.91 - Unauthenticated Stored XSS via Comment Author Email

The Anti-Spam, Spam FireWall by CleanTalk WordPress plugin before 6.91 does not escape a commenter-supplied value before outputting it on an administrative spam-review screen, allowing unauthenticated users to inject arbitrary web scripts that execute in the browser of an administrator who reviews flagged comments.