HaxCMS has a stored Cross-Site Scripting (XSS) bypass in saveNode endpoint

published 2026-05-29 5 mo ago modified 2026-09-10 1 mo ago also EUVD-2026-33286 , GHSA-g2g8-95qg-v35h

cvss: 8.7; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 13%
public exploits: 0; none known

HAX CMS helps manage microsite universe with PHP or NodeJs backends. Versions up to and including 26.0.0 are affected by a stored cross-site scripting (XSS) vulnerability in the `/system/api/saveNode` endpoint. An authenticated user with a permission to edit pages can bypass the HTML sanitizer by injecting an event handler attribute without whitespace before the attribute name. @haxtheweb/haxcms-nodejs 26.0.1 and haxcms-php 26.0.2 patch the issue.

Patch / fix

fixed in 6

npm @haxtheweb/haxcms-nodejs 26.0.1
haxtheweb hax 26.0.1, 26.0.2
haxtheweb haxcms-php 26.0.2
psu haxcms-php 26.0.2
haxtheweb haxcms-nodejs 26.0.1
psu haxcms-nodejs 26.0.1

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: total
Assessed: 5 mo ago (2026-05-29)

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 13% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/haxtheweb/issues/security/advisories/GHSA-g2g8-95qg-v35h referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.7	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
GitHub	3.1	8.7	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

Affected packages

ecosystem	package	affected	fixed in
npm	@haxtheweb/haxcms-nodejs	<26.0.1	26.0.1

Affected products

haxtheweb haxcms-nodejs
haxtheweb haxcms-php

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

github.com /haxtheweb/issues/security/advisories/GHSA-g2g8-95qg-v35h
exploit, web
nvd.nist.gov /vuln/detail/CVE-2026-48527
advisory
github.com /haxtheweb/issues
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary