CVE-2026-47244

NameCVE-2026-47244
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, DefaultHttp2Connection.DefaultEndpoint initialises maxActiveStreams/maxStreams to Integer.MAX_VALUE, and Http2Settings never inserts SETTINGS_MAX_CONCURRENT_STREAMS by default (Http2Settings.java:305-307 only clamps a user-supplied value). Unless the application explicitly calls initialSettings().maxConcurrentStreams(n), a Netty HTTP/2 server advertises no limit and enforces none locally. Each open stream allocates a DefaultStream object, PropertyMap slots, flow-controller state and IntObjectHashMap entry; with ~2^30 permissible odd stream IDs a single TCP connection can create hundreds of thousands of long-lived stream objects. This is also the precondition for CVE-2023-44487-style Rapid-Reset amplification, where the absence of a low concurrent cap multiplies backend work. 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-5x3r-wrvg-rp6q

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