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Fencer Vulns
high 8.5

CVE-2025-49137 json

Hax CMS Stored Cross-Site Scripting vulnerability

published 2025-06-09 17 mo ago modified 2026-09-10 1 mo ago also EUVD-2025-17562 , GHSA-2vc4-3hx7-v7v7

cvss
8.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 22%
public exploits
0
none known

Summary

HAX CMS PHP allows users to manage their microsite universe with a PHP backend. Prior to version 11.0.0, the application does not sufficiently sanitize user input, allowing for the execution of arbitrary JavaScript code. The 'saveNode' and 'saveManifest' endpoints take user input and store it in the JSON schema for the site. This content is then rendered in the generated HAX site. Although the application does not allow users to supply a `script` tag, it does allow the use of other HTML tags to run JavaScript. Version 11.0.0 fixes the issue.

Patch / fix

  • packagist elmsln/haxcms 11.0.0
  • haxtheweb hax 11.0.0
  • haxtheweb haxcms-php 11.0.0
  • psu haxcms-php 11.0.0

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
16 mo ago

Exploit prediction

0.29% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/haxtheweb/issues/security/advisories/GHSA-2vc4-3hx7-v7v7 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N
GitHub 3.1 8.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N
NVD 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
packagist elmsln/haxcms
<11.0.0
11.0.0

Affected products

  • haxtheweb issues

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation
  • CWE-80 Improper Neutralization of Script-Related HTML Tags in a Web Page
  • CWE-87 Improper Neutralization of Alternate XSS Syntax

References

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.