CVE-2026-56816
HIGHNetty: Memory Exhaustion via HTTP/3 Reserved Frame Types
Title source: cnaDescription
Netty is a network application framework for development of protocol servers and clients. Prior to 4.2.16.Final, Netty's `Http3FrameCodec` buffers incoming data for HTTP/3 reserved frame types up to the wire-specified payload length without limits; `decodeFrame` trusts `payLoadLength`, allowing an attacker to open multiple QUIC streams and send reserved frames with very large payload lengths to cause memory exhaustion and denial of service. This issue is fixed in version 4.2.16.Final.
References (3)
Core 3
Core References
X_Refsource_Confirm x_refsource_confirm
https://github.com/netty/netty/security/advisories/GHSA-hpcc-26xq-25fv
X_Refsource_Misc x_refsource_misc
https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b
X_Refsource_Misc x_refsource_misc
https://github.com/netty/netty/releases/tag/netty-4.2.16.Final
Scores
CVSS v3
7.5
EPSS
0.0043
EPSS Percentile
35.1%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-400
Status
published
Products (3)
io.netty/netty-codec-http3
0 - 4.2.16.FinalMaven
netty/netty
< 4.2.16
netty/netty
< 4.2.16.Final
Published
Jul 21, 2026
Tracked Since
Jul 22, 2026