# Regular expression denial of service in react-native

Advisory record · `GHSA-7f53-fmmv-mfjv`

- **Identifiers:** `GHSA-7f53-fmmv-mfjv` · `CVE-2020-1920`
- **State:** Confirmed
- **Severity:** CVSS 7.5 High
- **Critical:** No
- **Weakness (CWE):** [CWE-400](https://cwe.mitre.org/data/definitions/400.html) · [CWE-697](https://cwe.mitre.org/data/definitions/697.html) · [CWE-1333](https://cwe.mitre.org/data/definitions/1333.html)
- **Tags:** [Denial of service](https://agentprime.io/advisories/tag/dos.md) · [CWE-697](https://agentprime.io/advisories/tag/cwe-697.md)
- **Published:** 20 Jul 2021
- **Updated:** 8 Nov 2023
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 20 Jul 2021, 17:33 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `react-native` (npm): affected `>=0.59.0, <0.62.3 || >=0.63.0, <0.64.1`; fixed in `0.62.3`, `0.64.1`

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 7.5 High, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`, from GitHub Advisory Database

- **CISA KEV:** Not listed.
- **EPSS:** 0.014, the 71st percentile, on 6 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the GitHub Advisory Database, published 20 Jul 2021. New records show when each source confirmed them.

## Sources

- [GitHub Advisory Database: GHSA-7f53-fmmv-mfjv](https://github.com/advisories/GHSA-7f53-fmmv-mfjv)
- [OSV: GHSA-7f53-fmmv-mfjv](https://osv.dev/vulnerability/GHSA-7f53-fmmv-mfjv)
- <https://nvd.nist.gov/vuln/detail/CVE-2020-1920>
- <https://github.com/facebook/react-native/commit/ca09ae82715e33c9ac77b3fa55495cf84ba891c7>
- <https://github.com/facebook/react-native/releases/tag/v0.62.3>
- <https://github.com/facebook/react-native/releases/tag/v0.64.1>
- <https://securitylab.github.com/advisories/GHSL-2020-293-redos-react-native>
- <https://www.npmjs.com/package/react-native>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-7f53-fmmv-mfjv>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

---

The web page: <https://agentprime.io/advisories/GHSA-7f53-fmmv-mfjv/>. Everything for agents: <https://agentprime.io/llms.txt>.