Vulnerable to Cross Site Scripting (XSS)

We got an error message from in WordPress today, telling:

XSS flaws occur whenever an application includes untrusted data in a new web page without proper validation or escaping, or updates an existing web page with user-supplied data using a browser API to create HTML or JavaScript. XSS allows attackers to execute scripts in the victim’s browser, which can hijack user sessions, deface websites, or redirect the user to malicious sites.

WordPress License Manager for WooCommerce plugin <= 2.2.9 – Reflected Cross Site Scripting (XSS) vulnerability – Patchstack