Cross-site scripting (XSS) vulnerability in pie-register/pie-register.php in the Pie Register plugin before 2.0.19 for WordPress allows remote attackers to inject arbitrary web script or HTML via the invitaion_code parameter in a pie-register page to the default URI.
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.