CVE-2026-41305

unknown

Published 2026-04-24 · Modified 2026-05-06

CVSS v3

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CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CVSS v2

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VIR risk

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Description

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.

Predictions

Exploit likelihood

30%

Patch ETA

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Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2026-41305

OS impact

OS	Version	Status	Fixed in
debian	bookworm	affected
debian	bullseye	affected
debian	forky	fixed	`8.5.12+~cs9.3.32-1`
debian	sid	fixed	`8.5.12+~cs9.3.32-1`
debian	trixie	affected

Package impact

Ecosystem	Package	Vulnerable	Fixed
npm	postcss	`<8.5.10`	`8.5.10`

References

Verify integrity in audit chain (admin only). AS-IS.