HAX CMS: Stored XSS via '<video-player>' component allows arbitrary JavaScript execution and token theft
Date: 2026-05
Affected: npm/@haxtheweb/video-player, npm/@haxtheweb/haxcms-nodejs
Attack vector: xss
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2026-46496
CWE: CWE-116
CWE-79

### Summary A stored cross-site scripting (XSS) vulnerability exists in HAX CMS 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. ### Details The vulnerability is present in the `<video-player>` web component used within the HAX CMS editor. The application fails to validate or sanitize user-supplied input in the following attributes: - `source` - `source-data` These attributes accept arbitrary URI schemes, including `javascript:`, which leads to execution of attacker-controlled JavaScript in the browser. Example vulnerable usage: ```html <video-player source="javascript:alert(document.domain)" source-type="external"> </video-player> ``` Because this content is stored and rendered to other users, the vulnerability is classified as a stored XSS. The root cause is the lack of URI scheme validation and improper sanitization of component attributes before rendering. Because this content is stored and rendered to other users, the vulnerability is classified as a stored XSS. The root cause is the lack of URI scheme validation and improper sanitization of component attributes before rendering. ### PoC Steps to reproduce: 1. Log in to HAX CMS as user. 2. Create a website or any page and switch to t


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