WordPress Contact Form 7 Skins plugin 2.5.0 and prior contains a reflected cross-site scripting vulnerability. It does not sanitize and escape the tab parameter before outputting it back in an admin page.
View the template here CVE-2021-25063.yaml
References:
https://wpscan.com/vulnerability/e2185887-3e53-4089-aa3f-981c944ee0bb