CVE-2026-41305mediumCWE-79

CVE-2026-41305: medium-severity vulnerability in postcss

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

Published

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13Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 6.1epss 0.2%
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Affected products
postcss · postcss
Related CVEs — postcss

In the same product, most dangerous first.

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