8.7

CVE-2026-55851

Netty codec-haproxy: Signed-Byte Sentinel Collision in HAProxyMessageDecoder Leads to Unbounded Memory Exhaustion

Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final up to (but not including) 4.2.16.Final, and 4.1.0.Final up to (but not including) 4.1.135, the `HAProxyMessageDecoder` in Netty's `codec-haproxy` module performs protocol version detection by reading the 13th byte as a signed Java `byte` and widening it to `int` without masking; a PROXY protocol v2 binary prefix followed by version byte `0xFF` sign-extends to `-1`, collides with the decoder's need-more-data sentinel, and causes `ByteToMessageDecoder` to accumulate inbound bytes in an unbounded `cumulation` buffer until direct memory is exhausted. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
NettyNetty Version >= 4.1.0 < 4.1.136
NettyNetty Version >= 4.2.0 < 4.2.16
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.61% 0.459
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
NIST 7.5 3.9 3.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
security-advisories@github.com 8.7 0 0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CWE-400 Uncontrolled Resource Consumption

The product does not properly control the allocation and maintenance of a limited resource.

https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b
Patch
https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6
Patch
https://github.com/netty/netty/releases/tag/netty-4.1.136.Final
Release Notes
https://github.com/netty/netty/releases/tag/netty-4.2.16.Final
Release Notes
https://github.com/netty/netty/security/advisories/GHSA-q6cq-mhr2-jmr5
Vendor Advisory