The Popup Builder WordPress plugin before 4.0.7 does not validate and sanitise the sgpb_type parameter before using it in a require statement, leading to a Local File Inclusion issue. Furthermore, since the beginning of the string can be controlled, the issue can lead to RCE vulnerability via wrappers such as PHAR
https://wpscan.com/vulnerability/0f90f10c-4b0a-46da-ac1f-aa6a03312132