CVE-2026-46511 HAXcms: Mass Token Exfiltration and Cross-Tenant Hijack
An authenticated attacker can exploit Stored XSS to steal session tokens from the connection settings API, leading to cross-tenant account takeover.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-46511?
CVE-2026-46511 is a high-severity cross-site scripting vulnerability in haxtheweb haxcms-nodejs, published on 5 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
HAX CMS helps manage microsite universe with PHP or NodeJs backends. Prior to version 26.0.0, an attack chain utilizing Stored XSS alongside dynamic token exposure in the `/system/api/connectionSettings` endpoint allows an authenticated attacker to perform a complete cross-tenant account takeover. The API dynamically leaks the active session's authentication tokens (including the `jwt`, `user_token`, `site_token`, and `appstore_token`) into a global JavaScript variable (`window.appSettings`). An attacker can exploit the XSS vulnerability to force a victim's browser to silently fetch their specific connection settings, extract the tokens, and exfiltrate them to an attacker-controlled webhook. Version 26.0.0 patches the issue.
Which versions are affected by CVE-2026-46511?
2 open source packages ship an affected version, including @haxtheweb/haxcms-nodejs.
| Package | Affected | Fixed in |
|---|---|---|
@haxtheweb/haxcms-nodejs npm | All versions | 26.0.0 |
@haxtheweb/haxcms-nodejs npm | All versions | 26.0.0 |
How do I fix CVE-2026-46511?
Upgrade @haxtheweb/haxcms-nodejs to 26.0.0 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-46511 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-46511 exists.
Sources
Also known as GHSA-x3x5-7h4h-gwxg.