CVE-2026-84890
mediumpriority · track · 0EPSS 0.004 · 34 %ileDEFRUSEPSS · scored 2026-10-22
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
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (9)
Products and version ranges known to be affected.
- IBM WebSphere Service Registry and Repositoryall versionscert_bundDEcpe:/a:ibm:websphere_service_registry_and_repository:-
advisories (4)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-3596IBM App Connect Enterprise: Mehrere SchwachstellenDeutsch2026-09-27csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in IBM App Connect Enterprise ausnutzen, um Sicherheitsvorkehrungen zu umgehen, um einen Denial of Service Angriff durchzuführen, um Informationen offenzulegen, um Dateien zu manipulieren und um einen Cross-Site Scripting Angriff durchzuführen.
- GHSA-3xpg-4rpp-hhhmundici vulnerable to Denial of Service via unbounded decompression of compressed responses2026-09-29ghsa · osvUS
### Impact The `interceptors.decompress()` interceptor decompresses HTTP response bodies according to the untrusted `Content-Encoding` header. The number of decompression layers is capped at 5, but the total decompressed output size is not bounded and there is no option to limit it. A malicious or faulty upstream can return a small compressed payload (a compression bomb) that expands to hundreds of megabytes or gigabytes in client memory, exhausting memory and causing the Node.js process to crash or become unresponsive. Any application using the decompress interceptor to read responses from untrusted or compromised upstreams is affected. ### Patches Upgrade to `7.29.1` or `8.10.2`. The interceptor now accepts a `maxSize` option (default 64 MiB) and rejects responses whose decompressed output exceeds it with a `ResponseExceededMaxSizeError`. ### Workarounds Once upgraded, set a conservative `maxSize` on the interceptor. Before upgrading, avoid using `interceptors.decompress()` with untrusted upstreams, or apply a custom interceptor that enforces a decompressed output size limit.
- CERTFR-2026-AVI-1336Multiples vulnérabilités dans les produits IBMFrançais2026-10-16vendor · certfrFR
- CERTFR-2026-AVI-1378Multiples vulnérabilités dans les produits IBMFrançais2026-10-23vendor · certfrFR
sources
Which sources assert this record, and when.
references (2) nvd
External citations — patches, advisories, analysis.
- https://cna.openjsf.org/security-advisories.htmlVendor Advisory
- https://github.com/nodejs/undici/security/advisories/GHSA-3xpg-4rpp-hhhmMitigationVendor Advisory
Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.
Free scan