Netty netty-codec-haproxy 4.1.x/4.2.x Memory Leak via HAProxyMessage TLV
CVE-2026-44893 Published on June 12, 2026
Netty: HAProxy SSL TLV parsing leaks retained slice on invalid TLV length
Netty is a network application framework for development of protocol servers and clients. In netty-codec-haproxy prior to versions 4.1.135.Final and 4.2.15.Final, when decoding a PP2_TYPE_SSL TLV, HAProxyMessage.readNextTLV() first calls `header.retainedSlice(header.readerIndex(), length)` and only then reads the 1-byte client field and 4-byte verify field. If the attacker sets the TLV length below 5, the subsequent readByte/readInt throws IndexOutOfBoundsException. HAProxyMessageDecoder only catches HAProxyProtocolException around this call, so the IOOBE propagates and the retained slice on the pooled cumulation buffer is never released. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
Vulnerability Analysis
CVE-2026-44893 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
Improper Check or Handling of Exceptional Conditions
The software does not properly anticipate or handle exceptional conditions that rarely occur during normal operation of the software.
Products Associated with CVE-2026-44893
Want to know whenever a new CVE is published for Netty? stack.watch will email you.
Affected Versions
netty:- Version >= 4.2.0.Final, < 4.2.15.Final is affected.
- Version < 4.1.135.Final is affected.