CVE-2026-42583

Name	CVE-2026-42583
Description	Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Lz4FrameDecoder allocates a ByteBuf of size decompressedLength (up to 32 MB per block) before LZ4 runs. A peer only needs a 21-byte header plus compressedLength payload bytes - 22 bytes if compressedLength == 1 - to force that allocation. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
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)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
netty (PTS)	bullseye	1:4.1.48-4+deb11u2	vulnerable
	bullseye (security)	1:4.1.48-4+deb11u3	vulnerable
	bookworm	1:4.1.48-7+deb12u1	vulnerable
	bookworm (security)	1:4.1.48-7+deb12u2	vulnerable
	trixie	1:4.1.48-10	vulnerable
	trixie (security)	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)

https://github.com/netty/netty/security/advisories/GHSA-mj4r-2hfc-f8p6