The Martins Free & Easy SEO BackLink Link Building Network WordPress plugin before 1.2.30 does not sanitise and escape a parameter before outputting it back in the page, leading to a Reflected Cross-Site Scripting which could be used against high privilege users such as admin
https://wpscan.com/vulnerability/c0a6c253-71f2-415d-a6ec-022f2eafc13b