CVE-2026-56816CWE-400denial-of-service

CVE-2026-56816

High · published July 22, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
50.3
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00644 · 50.3th percentile
Weakness
CWE-400 · Uncontrolled Resource Consumption
Published
2026-07-22T02:17Z
Affected products (1)
ProductVersionsFixed in
netty/netty≥ 4.2.2, < 4.2.164.2.16
References (3)
https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b · [email protected]https://github.com/netty/netty/releases/tag/netty-4.2.16.Final · [email protected]https://github.com/netty/netty/security/advisories/GHSA-hpcc-26xq-25fv · [email protected]
EPSS history
Timeline
  • 21 JUL 21:56Z
    Netty: Memory Exhaustion via HTTP/3 Reserved Frame Types
    cvelistv5