Typesetter CMS versions up to and including 5.1 contain a reflected cross-site scripting (XSS) vulnerability in the Editing component. The images parameter (submitted as images[] in a POST request) is reflected into an HTML href attribute without proper context-aware output encoding in include/tool/Editing.php. An authenticated attacker with editing privileges can supply a JavaScript pseudo-protocol (e.g., javascript:) to trigger arbitrary JavaScript execution in the context of the victim's browser session.