CVE-2026-84890

Description

undici's decompress interceptor decompresses response bodies according to the untrusted Content-Encoding header. While the number of content-encoding layers is capped, the total decompressed output size is unbounded and there is no configuration option to limit it. A malicious or faulty upstream can therefore return a small compressed payload, a compression bomb, that expands to hundreds of megabytes or more in client memory, an asymmetric resource consumption that can exhaust memory and crash the process. This affects undici versions from 7.15.0 up to 7.29.1 and from 8.0.0 up to 8.10.2. Users should upgrade to undici 7.29.1 or 8.10.2.

CVSS Metrics

• v3.1•MEDIUM•Score: 5.9CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 0.25%• Percentile: 17%

Techniques & Countermeasures

• CWE-770•Allocation of Resources Without Limits or Throttling

  The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

Affected Systems

• chainguard•node-gyp

  < 13.0.2-r1

• wolfi•node-gyp

  < 13.0.2-r1

• debian•node-undici

  all | all | all | < 8.10.2+dfsg+~cs3.2.2-1

• ubuntu•node-undici

  all | all

• nodejs•undici

  ≥ 7.15.0, < 7.29.1 | ≥ 8.0.0, < 8.10.2

• undici•undici

  ≥ 7.15.0, < 7.29.1 | ≥ 8.0.0, < 8.10.2

References (5)

• https://github.com/nodejs/undici/security/advisories/GHSA-3xpg-4rpp-hhhm
• https://cna.openjsf.org/security-advisories.html
• https://security-tracker.debian.org/tracker/CVE-2026-84890
• https://ubuntu.com/security/CVE-2026-84890
• https://www.cve.org/CVERecord?id=CVE-2026-84890