CVE-2026-87029 Affecting node-undici package, versions <8.12.2+dfsg+~cs3.2.3-1


Severity

Recommended
0.0
high
0
10

Snyk's Security Team recommends NVD's CVSS assessment. Learn more

Threat Intelligence

EPSS
0.26% (17th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-DEBIANUNSTABLE-NODEUNDICI-20977355
  • published16 Oct 2026
  • disclosed15 Oct 2026

Introduced: 15 Oct 2026

NewCVE-2026-87029  (opens in a new tab)

How to fix?

Upgrade Debian:unstable node-undici to version 8.12.2+dfsg+~cs3.2.3-1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream node-undici package and not the node-undici package as distributed by Debian. See How to fix? for Debian:unstable relevant fixed versions and status.

undici is an HTTP client library for Node.js. In versions 7.15.0 through 7.30.0 and 8.0.0 through 8.12.1, its decompress interceptor forwards decompressed response data to the downstream handler from zlib stream event callbacks without catching exceptions those callbacks may throw, and while undici's engine converts a synchronous throw from a downstream handler into a per-request failure, that protection is absent when the throw happens asynchronously from a zlib callback. As a result, a downstream handler that throws by design, such as the built-in dump interceptor which throws when a response exceeds its configured maximum size, escapes as an uncaught exception that terminates the Node.js process. A malicious or compromised HTTP server can crash any client that composes the decompress interceptor with such a handler by returning a small compressed body that decompresses to more than the configured limit, so only the decompressed size matters and the bytes on the wire stay tiny. The issue is fixed in undici 7.30.1 and 8.12.2, and users should upgrade to one of those versions or later. As a workaround, avoid composing the decompress interceptor with a response handler that throws during response processing until upgrading.

CVSS Base Scores

version 3.1