CVE-2026-84890

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.

Score
CVSS 3.1 5.9 Medium
Status
Analyzed - ce714d77-add3-4f53-aff5-83d477b104bb
Published
2026-09-04
Last modified
2026-09-04
Weaknesses
CWE-770

Affected products

References