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OpenAdvisories
Medium · 5.9 CVE-2026-87029 EUVD-2026-102347GHSA-55wc-3pg8-jfw6

undici vulnerable to Denial of Service via unhandled exception in the decompress interceptor

Published Oct 15, 2026 · Updated Oct 16, 2026 · Assigned by openjs

Description

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.

Affected products

VendorProductAffectedFixed
undici undici 7.15.0 – < 7.30.1, 8.0.0 – < 8.12.2 7.30.1

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 node-undici 8.12.2+dfsg+~cs3.2.3-1 —
Debian 13 node-undici No fix yet —
Debian 12 node-undici No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 node-undici No fix yet —
Ubuntu 26.04 LTS node-undici No fix yet —
Ubuntu 24.04 LTS node-undici No fix yet —
ReleasePackageFixed inAdvisory
Red Hat Hardened Images 1 nodejs24 +6 24.21.0-1.5.hum1 RHSA-2026:84706
Red Hat Hardened Images 1 nodejs24-npm 11.19.0-1.24.21.0.1.5.hum1 RHSA-2026:84706
Red Hat Hardened Images 1 v8-13.6-devel 13.6.233.17-1.24.21.0.1.5.hum1 RHSA-2026:84706

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 nodejs24 +4 1:24.22.1-1.amzn2023.0.1 ALAS2023-2026-3330
Amazon Linux 2023 nodejs24-npm 1:11.19.1-1.24.22.1.1.amzn2023.0.1 ALAS2023-2026-3330
Amazon Linux 2023 v8-13.6-devel 3:13.6.233.17-1.24.22.1.1.amzn2023.0.1 ALAS2023-2026-3330

Wolfi

ReleasePackageFixed inAdvisory
Wolfi rolling node-gyp 13.1.0-r1 —
Wolfi rolling renovate 44.198.3-r1 —

Affected packages

EcosystemPackageAffectedFixedRecord
npm undici >= 7.15.0, < 7.30.1 7.30.1 GHSA-55wc-3pg8-jfw6
npm undici >= 8.0.0, < 8.12.2 8.12.2 GHSA-55wc-3pg8-jfw6

Advisories 2

References