CVE-2026-89044
mediumpriority · track · 26EPSS 0.003 · 20 %ileDEFRUSEPSS · scored 2026-10-24
Netty versions 4.1.133.Final through 4.1.137.Final and 4.2.13.Final through 4.2.17.Final fail to properly validate the final transfer coding in the Transfer-Encoding header, allowing attackers to smuggle requests by using malformed encoding declarations. Attackers can split Transfer-Encoding headers across multiple lines or use values like 'chunked, xchunked' to bypass validation and decode messages as chunked when the final coding is not chunked, enabling request smuggling attacks.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 2.7–6.9
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (10)
Products and version ranges known to be affected.
advisories (3)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-3291Netty: Mehrere SchwachstellenDeutsch2026-09-09csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Netty ausnutzen, um Denial-of-Service-Zustände zu verursachen, Sicherheitsmaßnahmen zu umgehen, Request- oder Response-Smuggling durchzuführen sowie Daten offenzulegen oder zu manipulieren.
- CERTFR-2026-AVI-1336Multiples vulnérabilités dans les produits IBMFrançais2026-10-16vendor · certfrFR
- CERTFR-2026-AVI-1349Multiples vulnérabilités dans Oracle Database ServerFrançais2026-10-21vendor · certfrFR
sources
Which sources assert this record, and when.
references (8) nvd
External citations — patches, advisories, analysis.
- https://github.com/netty/nettyProduct
- https://github.com/netty/netty/blob/netty-4.1.137.Final/codec-http/src/main/java/io/netty/handler/codec/http/HttpObjectDecoder.java#L866Product
- https://github.com/netty/netty/commit/640d4d3324f7b811a4903d0730c8ccb35500500cPatch
- https://github.com/netty/netty/commit/ca87393b0e9e13c493d213a268e727a6d44e1585Patch
- https://github.com/netty/netty/releases/tag/netty-4.1.138.FinalRelease Notes
- https://github.com/netty/netty/releases/tag/netty-4.2.18.FinalRelease Notes
- https://github.com/netty/netty/security/advisories/GHSA-hcvj-94mj-jp5cExploitVendor Advisory
- https://www.vulncheck.com/advisories/netty-4.1.133-final-through-4.1.137-final-and-4.2.13-final-through-4.2.17-final-http-request-smuggling-via-transfer-encodingPatchThird Party Advisory
Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.
Free scan