CVE-2026-41305
Published:April 24, 2026
Updated:April 24, 2026
PostCSS takes a CSS file and provides an API to analyze and modify its rules by transforming the rules into an Abstract Syntax Tree. Versions prior to 8.5.10 do not escape "</style>" sequences when stringifying CSS ASTs. When user-submitted CSS is parsed and re-stringified for embedding in HTML "<style>" tags, "</style>" in CSS values breaks out of the style context, enabling XSS. Version 8.5.10 fixes the issue.
Affected Packages
https://github.com/postcss/postcss.git (GITHUB):
Affected version(s) >=0.1 <8.5.10Fix Suggestion:
Update to version 8.5.10postcss (NPM):
Affected version(s) >=0.1.0 <8.5.10Fix Suggestion:
Update to version 8.5.10postcss (NPM):
Affected version(s) >=0.1.0 <8.5.10Fix Suggestion:
Update to version 8.5.10Related Resources (4)
Do you need more information?
Contact UsCVSS v4
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
PASSIVE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
LOW
Subsequent System Integrity
LOW
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
