CVE-2026-48059
Published:June 12, 2026
Updated:June 29, 2026
Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, the HAProxy PROXY protocol v2 codec in netty leaks native or heap memory on every connection when a client sends a syntactically valid header containing nested "PP2_TYPE_SSL" TLVs (type-length-value records) at depth two or greater. The leak occurs on the successful parse path — no exception is thrown, the message fires downstream, the decoder removes itself, and the application releases the "HAProxyMessage" normally. Yet the underlying cumulation buffer (a pooled, potentially direct "ByteBuf" allocated by the channel) remains permanently pinned. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
Affected Packages
https://github.com/netty/netty.git (GITHUB):
Affected version(s) >=netty-tag <4.1.135.FinalFix Suggestion:
Update to version 4.1.135.Finalio.netty:netty-codec-haproxy (JAVA):
Affected version(s) >=4.2.0.Final <4.2.15.FinalFix Suggestion:
Update to version 4.2.15.Finalio.netty:netty-codec-haproxy (JAVA):
Affected version(s) >=4.0.29.Final <4.1.135.FinalFix Suggestion:
Update to version 4.1.135.FinalRelated Resources (5)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Missing Release of Memory after Effective Lifetime
EPSS
Base Score:
0.43