Vulnerabilities

Vulnerability · CVE-2026-87029

undici is an HTTP client library for Node.js.

Published Oct 15, 2026 · catalog updated Oct 15, 2026 · undici is an HTTP

Check if you run it

No confirmed exploitation is on record for CVE-2026-87029. EPSS is 0.25%. Act only if a listed version of undici is an HTTP is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (undici is an HTTP).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Medium5.9
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.25%
Remediation
Advisory link
Affected products
Debian:12 node-undici · Debian:13 node-undici · Debian:14 node-undici · vendor undici undici

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • Debian:12 node-undici5.15.0+dfsg1+~cs20.10.9.3-1, 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u1, 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u2
  • Debian:13 node-undici7.15.0+dfsg+~cs3.2.0-1, 7.15.0+dfsg+~cs3.2.0-3, 7.16.0+dfsg+~cs3.2.0-1
  • Debian:14 node-undici7.15.0+dfsg+~cs3.2.0-1, 7.15.0+dfsg+~cs3.2.0-3, 7.16.0+dfsg+~cs3.2.0-1
  • vendor undici undiciversion unspecified

How to fix CVE-2026-87029

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-87029. EPSS is 0.25%. Act only if a listed version of undici is an HTTP is installed.

Which versions are affected?

Compare what you have installed with 5.15.0+dfsg1+~cs20.10.9.3-1, 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u1, 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u2, 7.15.0+dfsg+~cs3.2.0-1, 7.15.0+dfsg+~cs3.2.0-3, 7.16.0+dfsg+~cs3.2.0-1. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-248. EPSS 0.25%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 15, 2026 · NIST NVD

    Detected

    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 pro

  2. Oct 15, 2026 · OpenSSF OSV / OSV Scanner

    Updated

    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 pro

Sources

  • CVE.orgVulnerability recordCVE-2026-87029

    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 thro

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-87029

    30-day exploitation probability 0.3%

    first.org
  • NIST NVDVulnerability recordCVE-2026-87029

    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 thro

    nvd.nist.gov
  • OpenSSF OSV / OSV ScannerPackage advisoryDEBIAN-CVE-2026-87029
    osv.dev

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.