6.1

CVE-2026-41305

PostCSS has XSS via Unescaped </style> in its CSS Stringify Output

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.
Daten sind bereitgestellt durch das CVE Programm von einer CVE Numbering Authority (CNA) (Unstrukturiert).
Herstellerpostcss
Produkt postcss
Version < 8.5.10
Status affected
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.21% 0.104
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
security-advisories@github.com 6.1 2.8 2.7
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

https://github.com/postcss/postcss/security/advisories/GHSA-qx2v-qp2m-jg93
https://github.com/postcss/postcss/releases/tag/8.5.10