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CVE-2026-56816

Netty: Memory Exhaustion via HTTP/3 Reserved Frame Types

Published: Jul 21, 2026Updated: Aug 7, 2026 Sources: CVE List NVDCWE-400
7.5HIGH
NVD MITRE
EPSS Score
0.5%
Top 58.5%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
Not available

Description

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
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Weaknesses

CWE-400

Affected Products

netty
oss-projectaka io.netty:netty, netty-incubator-codec-ohttp
nettyLibraryLibrary
OSS Libraries / generic-library

Exploitability

Official Patch Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Impact
View detailed technique mapping

References

https://github.com/netty/netty/security/advisories/GHSA-hpcc-26xq-25fv
github.com
https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b
github.com
https://github.com/netty/netty/releases/tag/netty-4.2.16.Final
github.com

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