CVE-2026-84890

Public on 2026-09-04
Modified on 2026-09-05
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.
Severity
Medium severity
Medium
See what this means
CVSS v3 Base Score
5.9
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 2023 nodejs No Fix Planned
Amazon Linux 2023 nodejs20 No Fix Planned
Amazon Linux 2023 nodejs22 Not Affected
Amazon Linux 2023 nodejs24 Pending Fix
Amazon Linux 2027 Preview nodejs24 Pending Fix

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H