The LearnPress WordPress plugin before 4.4.7 does not escape a user supplied value before using it in an HTML attribute on a public page, allowing unauthenticated attackers to execute arbitrary JavaScript in the browser of anyone who opens a crafted link, including a logged in administrator. Only sites running a classic, non-block are affected.
https://wpscan.com/vulnerability/c11f39bd-7db8-495f-9118-48b63ee0858f/