CVE-2026-50560

NameCVE-2026-50560
DescriptionNetty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty HTTP/2 max header size handling produces an attack similar to HTTP/2 Rapid Reset. There is a setting in the http2 specification called `SETTINGS_MAX_HEADER_LIST_SIZE`. When a client sends that setting to Netty, it appears that Netty will behave as follows: read the request; proxy the request to the origin; attempt to produce a response; and create an exception while writing the headers for the response. Functionally, this should be similar to the http2 reset attack, but with a different on-the-wire signature. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
SourceCVE (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 Bugs1139914

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
netty (PTS)bullseye1:4.1.48-4+deb11u2vulnerable
bullseye (security)1:4.1.48-4+deb11u3vulnerable
bookworm, bookworm (security)1:4.1.48-7+deb12u2vulnerable
trixie (security), trixie1:4.1.48-10+deb13u1vulnerable
forky, sid1:4.1.48-16vulnerable

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

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
nettysource(unstable)(unfixed)1139914

Notes

https://github.com/netty/netty/security/advisories/GHSA-563q-j3cm-6jxm

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