CVE-2026-73508

Name	CVE-2026-73508
Description	Netty is an asynchronous, event-driven network application framework. Prior to 4.1.136.Final and 4.2.16.Final, io.netty.handler.codec.dns.AbstractDnsRecord, io.netty.handler.codec.dns.DefaultDnsRecordDecoder.decodeRecord(), and io.netty.handler.codec.dns.DnsCodecUtil.decompressDomainName() failed to release retained or newly allocated ByteBuf objects when IDN.toASCII() or encodeDomainName() rejected a malformed domain name, allowing unauthenticated remote DNS packets to leak direct memory incrementally until denial of service. This issue is fixed in versions 4.1.136.Final and 4.2.16.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)
Debian Bugs	1144384

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)			1144384

Notes

https://github.com/netty/netty/security/advisories/GHSA-mfg7-5gfp-c4w3
https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b (netty-4.2.16.Final)
https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6 (netty-4.1.136.Final)