Update the WordPress YARPP plugin to the latest available version (at least 5.30.5).
Rafie Muhammad (Patchstack) discovered and reported this Local File Inclusion vulnerability in WordPress YARPP Plugin. This could allow a malicious actor to include local files of the target website and show its output onto the screen. Files which store credentials, such as database credentials, could potentially allow complete database takeover depending on the configuration. This vulnerability has been fixed in version 5.30.5.