HAX CMS helps manage microsite universe with PHP or NodeJs backends. A stored cross-site scripting (XSS) vulnerability exists in versions prior to 26.0.0 due to improper sanitization of the <video-player> component. The component allows javascript: URIs in the source attribute, which are executed when the page is viewed. This enables attackers to execute arbitrary JavaScript in the context of the victim’s browser and access sensitive data such as JWT tokens and more. Version 26.0.0 fixes the issue.