CVE-2026-41305
PostCSS has XSS via Unescaped </style> in its CSS Stringify Output
MEDIUM 6.1EPSS 0.3%
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
- postcss
- CVSS v3.1 GITHUB
- 6.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - EPSS
- 0.26% chance of exploitation in the next 30 days, 17th percentile
- Published
- 2026-04-24