Medium severity6.5NVD Advisory· Published Sep 10, 2026· Updated Sep 10, 2026
CVE-2026-89044
CVE-2026-89044
Description
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.
Affected products
2Patches
Vulnerability mechanics
References
7- github.com/netty/netty/blob/netty-4.1.137.Final/codec-http/src/main/java/io/netty/handler/codec/http/HttpObjectDecoder.javanvd
- github.com/netty/netty/commit/640d4d3324f7b811a4903d0730c8ccb35500500cnvd
- github.com/netty/netty/commit/ca87393b0e9e13c493d213a268e727a6d44e1585nvd
- github.com/netty/netty/releases/tag/netty-4.1.138.Finalnvd
- github.com/netty/netty/releases/tag/netty-4.2.18.Finalnvd
- github.com/netty/netty/security/advisories/GHSA-hcvj-94mj-jp5cnvd
- 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-encodingnvd
News mentions
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