CVE-2026-48527: HAX CMS stored XSS via sanitizer bypass in saveNode endpoint

CVE-2026-48527 · Severity: high · CVSS 8.7 · Published 2026-05-29

HaxCMS, a content management system, is vulnerable to a security flaw that allows users with page-editing permissions to inject malicious scripts into website pages. If another user, such as an administrator, views the affected page and interacts with the injected content, the attacker could steal sensitive session data or perform unauthorized actions on their behalf. This could lead to a full takeover of the site or unauthorized access to private data.

Technologies: @haxtheweb/haxcms-nodejs (npm). Vendors: npm.

Quick answers

Is CVE-2026-48527 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-48527 being exploited in the wild.
How severe is CVE-2026-48527?
High severity, with a CVSS score of 8.7, published 29 May 2026.
Which products and versions are affected?
@haxtheweb/haxcms-nodejs (npm) <= 26.0.0, SEMVER:introduced=0,fixed=26.0.1.
Is there a fix for CVE-2026-48527?
Yes. @haxtheweb/haxcms-nodejs (npm): upgrade to 26.0.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-48527 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-48527?
Check whether you run @haxtheweb/haxcms-nodejs (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • @haxtheweb/haxcms-nodejs (npm): upgrade to 26.0.1 or later
    npm install @haxtheweb/haxcms-nodejs@26.0.1

Technical details

A stored Cross-Site Scripting (XSS) vulnerability exists in HaxCMS versions up to 26.0.0 within the `/system/api/saveNode` endpoint. The vulnerability is caused by a flaw in the regex-based HTML sanitizer, which fails to identify and strip event handler attributes (like 'onclick') if they are not preceded by whitespace (e.g., `href="#"onclick="..."`). An authenticated attacker with page-editing privileges can submit a crafted `node.body` parameter to inject malicious JavaScript. When a victim interacts with the injected element, the script executes in their browser context, potentially exposing JWTs in localStorage or application settings. The issue is addressed in version 26.0.1.

Affected products

  • HaxTheWeb @haxtheweb/haxcms-nodejs <= 26.0.0

Identifiers

  • CVE-2026-48527
  • GHSA-g2g8-95qg-v35h

Timeline

  • 2026-05-21: disclosed: Vulnerability reported to vendor
  • 2026-05-29: advisory: GitHub Advisory published
  • 2026-05-29: patched: Version 26.0.1 released

References

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