CVE-2026-42582

Name	CVE-2026-42582
Description	Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final, when decoding header blocks, the non-Huffman branch of io.netty.handler.codec.http3.QpackDecoder#decodeHuffmanEncodedLiteral may execute new byte[length] for a string literal before verifying that length bytes are actually present in the compressed field section. The wire encoding allows a very large length to be expressed in few bytes. There is no check that length <= in.readableBytes() before new byte[length]. This vulnerability is fixed in 4.2.13.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, 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)

https://github.com/netty/netty/security/advisories/GHSA-2c5c-chwr-9hqw