---
id: CVE-2026-109869
title: undici is an HTTP client library for Node.js
summary: >-
  undici is an HTTP client library for Node.js. In versions 6.23.0 through
  6.29.0, 7.18.0 through 7.30.0, and 8.0.0 through 8.12.1, its fetch()
  implementation crashes the Node.js process when a malicious server returns a
  response with more…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-248
  - CWE-459
vendor: undici
product: undici
affected:
  - undici >= 6.23.0 < 6.29.1
  - undici >= 7.18.0 < 7.30.1
  - undici >= 8.0.0 < 8.12.2
published: '2026-10-15'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T19:17:21.770'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-109869'
references:
  - url: 'https://cna.openjsf.org/security-advisories.html'
    label: ce714d77-add3-4f53-aff5-83d477b104bb
  - url: 'https://github.com/nodejs/undici/security/advisories/GHSA-xjj6-f33q-929c'
    label: ce714d77-add3-4f53-aff5-83d477b104bb
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-15T19:25:46.400Z'
---

## Overview

undici is an HTTP client library for Node.js. In versions 6.23.0 through 6.29.0, 7.18.0 through 7.30.0, and 8.0.0 through 8.12.1, its fetch() implementation crashes the Node.js process when a malicious server returns a response with more than five content codings and closes the connection before sending the body. undici rejects such responses because of a content-encoding limit, but it created the internal response stream before that check and returned without attaching an error listener or aborting the request, so the early close surfaces a content-length mismatch on the orphaned stream, which Node.js treats as an unhandled error and terminates the process. A remote, unauthenticated server can trigger this with a single response, even when the application correctly catches the fetch() rejection, resulting in a denial of service. The issue is fixed in undici 6.29.1, 7.30.1, and 8.12.2, and users should upgrade to one of those versions or later. There is no workaround.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.