---
id: CVE-2026-84890
title: >-
  undici's decompress interceptor decompresses response bodies according to the
  untrusted Content-Encoding header
summary: >-
  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
  confi…
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-770
  - CWE-409
vendor: nodejs
product: undici
affected:
  - 'undici >= 7.15.0, < 7.29.1'
  - 'undici >= 8.0.0, < 8.10.2'
patched:
  - undici 8.10.2
published: '2026-09-04'
updated: '2026-09-11'
sourceUpdated: '2026-09-11T16:55:29.047'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84890'
references:
  - url: 'https://cna.openjsf.org/security-advisories.html'
    label: ce714d77-add3-4f53-aff5-83d477b104bb
  - url: 'https://github.com/nodejs/undici/security/advisories/GHSA-3xpg-4rpp-hhhm'
    label: ce714d77-add3-4f53-aff5-83d477b104bb
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-84890.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-84890'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2528772'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-84890'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84890'
  - url: 'https://access.redhat.com/errata/RHSA-2026:66008'
  - url: 'https://access.redhat.com/errata/RHSA-2026:54438'
  - url: 'https://access.redhat.com/errata/RHSA-2026:54389'
tags:
  - nvd
  - csaf
  - vex
  - red-hat
epss: 0.00412
epssPercentile: 0.32783
ingestedAt: '2026-09-08T19:08:49.594Z'
---

## Overview

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.

## Affected

- `undici >= 7.15.0, < 7.29.1`
- `undici >= 8.0.0, < 8.10.2`

## Remediation

Upgrade past the affected range:

- `undici 8.10.2`

## Vendor advisories

- **RHSA-2026:66008** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-09 · [advisory](https://access.redhat.com/errata/RHSA-2026:66008)
- **RHSA-2026:54438** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-08-12 · [advisory](https://access.redhat.com/errata/RHSA-2026:54438)
- **RHSA-2026:54389** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-08-12 · [advisory](https://access.redhat.com/errata/RHSA-2026:54389)
- **Red Hat VEX** · Moderate · affected: Exploit Intelligence, OpenShift Pipelines, Red Hat AMQ Broker 7, Red Hat Ansible Automation Platform 2, Red Hat Build of Podman Desktop, Red Hat Developer Hub, … · no fix planned: Exploit Intelligence, Red Hat Trusted Artifact Signer, Secrets Management Console for Red Hat OpenShift, Red Hat Hardened Images, … · updated 2026-09-09 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-84890.json)