High severity · published Jun 12, 2026
CVE-2026-48059
Netty HAProxy: Unbalanced Reference Count in Nested PP2_TYPE_SSL TLV Parsing Leads to Memory Exhaustion
7.5
CVSS
0.6%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 50% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NE
netty · netty
>= 4.2.0.Final, < 4.2.15.Final; < 4.1.135.Final · source: vendor, NVD
C4
Cryostat 4 on RHEL 9 · Red Hat
All versions, or not specified · source: CISA
OS
OpenShift Serverless · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat AMQ Broker 7.14.1 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Build of Apache Camel 3.33 for Quarkus 3.33.2.SP1 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Build of Keycloak · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Data Grid 8.6.2 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Fuse 7 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat JBoss Enterprise Application Platform 8.1 · Red Hat
All versions, or not specified · source: CISA
Affected product
NE
netty
netty
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