CVSS 3.1
6.1 mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:NCVE-2026-41305
Medium (6.1). EPSS 0.2% chance of exploitation in the next 30 days. Fixed in postcss 8.5.10.
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.
Severity
- EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 10% of CVEs (scores of 2026-10-31)
- CWE
- CWE-79
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-qx2v-qp2m-jg93 | npm | postcss | <8.5.10 | 8.5.10 |