Xibo is an open source digital signage platform with a web content management system (CMS). Prior to version 4.1.0, a cross-site scripting vulnerability in Xibo CMS allows authorized users to execute arbitrary JavaScript via the file preview function. Users can upload HTML/CSS/JS files into the Xibo Library via the Generic File module to be referenced on Displays and in Layouts. This is intended functionality. When previewing these resources from the Library and Layout editor they are executed in the users browser. This will be disabled in future releases, and users are encouraged to use the new developer tools in 4.1 to design their widgets which require this type of functionality. This behavior has been changed in 4.1.0 to preview previewing of generic files. There are no workarounds for this issue.