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.
Weakness
The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Netty | Netty | * | 4.1.135 (excluding) |
| Netty | Netty | 4.2.0 (including) | 4.2.15 (excluding) |
| Red Hat Build of Apache Camel 3.33 for Quarkus 3.33.2.SP1 | RedHat | netty-codec-haproxy | * |
| Red Hat build of Quarkus 3.27.4.SP1 | RedHat | netty-codec-haproxy | * |
| Red Hat build of Quarkus 3.33.2.SP1 | RedHat | netty-codec-haproxy | * |
| Streams for Apache Kafka 2.9.4 | RedHat | netty-codec-haproxy | * |
Potential Mitigations
- Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
- For example, glibc in Linux provides protection against free of invalid pointers.
- When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391].
- To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.
References
- https://github.com/netty/netty/releases/tag/netty-4.1.135.Final
- https://github.com/netty/netty/releases/tag/netty-4.2.15.Final
- https://github.com/netty/netty/security/advisories/GHSA-h2qv-fj59-j46j
- https://access.redhat.com/errata/RHSA-2026:26017
- https://access.redhat.com/errata/RHSA-2026:26018
- https://access.redhat.com/errata/RHSA-2026:26586
- https://access.redhat.com/errata/RHSA-2026:34608
- https://access.redhat.com/security/cve/CVE-2026-48059
- https://bugzilla.redhat.com/show_bug.cgi?id=2488437
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48059.json