Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in NotFound Top Bar – PopUps – by WPOptin allows Reflected XSS. This issue affects Top Bar – PopUps – by WPOptin: from n/a through 2.0.8.
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.