Netty HAProxy: Unbalanced Reference Count in Nested PP2_TYPE_SSL TLV Parsing Leads to Memory Exhaustion
### Impact 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.
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2026-48059US | high7.5 | — | ||
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 n… | ||||
references
External citations — patches, advisories, analysis.
- https://access.redhat.com/errata/RHSA-2026:26017WEB
- https://access.redhat.com/errata/RHSA-2026:26018WEB
- https://access.redhat.com/errata/RHSA-2026:26586WEB
- https://access.redhat.com/errata/RHSA-2026:34608WEB
- https://access.redhat.com/errata/RHSA-2026:36820WEB
- https://access.redhat.com/errata/RHSA-2026:37390WEB
- https://access.redhat.com/errata/RHSA-2026:41951WEB
- https://access.redhat.com/errata/RHSA-2026:48151WEB
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