CVE-2026-89044

Name	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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1147398

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
netty (PTS)	bookworm, bookworm (security)	1:4.1.48-7+deb12u2	vulnerable
	trixie (security), trixie	1:4.1.48-10+deb13u1	vulnerable
	forky, sid	1:4.1.48-16	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
netty	source	(unstable)	(unfixed)			1147398

Notes

https://github.com/netty/netty/security/advisories/GHSA-hcvj-94mj-jp5c
Fixed by: https://github.com/netty/netty/commit/640d4d3324f7b811a4903d0730c8ccb35500500c (netty-4.2.18.Final)
Fixed by: https://github.com/netty/netty/commit/ca87393b0e9e13c493d213a268e727a6d44e1585 (netty-4.1.138.Final)