TI-2020-03551 Aliases CVE-2020-4070

Cross-site Scripting in CSS Validator

LOW 25CWE-79Published 2020-06-22 · Updated 2024-08-04

Key facts

Attack vector: Network
Privileges required: Low
User interaction: Required
Attack complexity: Low
Impact type: Cross-site scripting
Confidentiality · integrity · availability: Low · Low · None
Fix status: No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-79.

Summary

In CSS Validator less than or equal to commit 54d68a1, there is a cross-site scripting vulnerability in handling URIs. A user would have to click on a specifically crafted validator link to trigger it. This has been patched in commit e5c09a9.

Why it matters now

EPSS 0.0055 46th percentileScored 2026-11-07

Fix No fix listed No fixed version in the sources yet

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
World Wide Web Consortium (W3C)	CSS Validator	up to 54d68a1	—	No fix listed	CNA

CSS Validator VendorWorld Wide Web Consortium (W3C) Affected up to 54d68a1 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:w3c:css_validator::::::::	up to 2020-01-19	Vulnerable	w3c

cpe:2.3:a:w3c:css_validator:*:*:*:*:*:*:*:* Versions up to 2020-01-19 Vulnerable ·w3c

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2020-4070

References

Patch 1

https://github.com/w3c/css-validator/commit/e5c09a9119167d3064db786d5f00d730b584a53b

Advisory 1

https://github.com/w3c/css-validator/security/advisories/GHSA-wf36-7w73-rh8c

Sources

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