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TI-2025-01533 Aliases CVE-2025-1781

XML external entity injection in w3c CSS Validator

Priority HIGH 76CWE-611Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
None · High · Low
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

There is a XXE in W3CSS Validator versions before cssval-20250226 that allows an attacker to use specially-crafted XML objects to coerce server-side request forgery (SSRF).  This could be exploited to read arbitrary local files if an attacker has access to exception messages.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00393 33rd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
w3cCSS Validator< cssval-20250226—No fix listedCNA
  • CSS Validator Vendorw3c Affected < cssval-20250226 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:w3:css_validator:*:*:*:*:*:*:*:*before 20250226VulnerableW3
  • cpe:2.3:a:w3:css_validator:*:*:*:*:*:*:*:* Versions before 20250226 Vulnerable ·W3

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-1781

References

Exploit 1

  • TI-2008-05027 Multiple stack-based buffer overflows in W3C Amaya Web Browser 10.0.1 allow remote… CVSS 2.0HIGH 10.0
  • TI-2008-05701 Multiple buffer overflows in the CheckUniqueName function in W3C Amaya Web Browser… CVSS 2.0HIGH 10.0
  • TI-2006-01845 Multiple buffer overflows in World Wide Web Consortium (W3C) Amaya 9.4, and possibly… CVSS 2.0HIGH 7.6
  • TI-2000-00079 The W3C CERN httpd HTTP server allows remote attackers to determine the real pathnames of… CVSS 2.0HIGH 7.5
  • TI-2002-01025 Cross-site scripting (XSS) vulnerability in W3C Jigsaw Proxy Server before 2.2.1 allows… CVSS 2.0MEDIUM 6.8
  • TI-2004-02146 Unknown vulnerability in Jigsaw before 2.2.4 has unknown impact and attack vectors… CVSS 2.0MEDIUM 6.4
See all 13 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences