The Advance Post Prefix WordPress plugin through 1.1.1, Advance Post Prefix WordPress plugin through 1.1.1 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/038b44dc-0495-4f56-ae7e-c78a265aa535/