CVE-2026-44893: 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 PP2TYPESSL 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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
maven/io.netty:netty-codec-haproxyto a version that resolves this vulnerability.Fixed in 4.1.135.Final - Upgrade
Upgrade
maven/io.netty:netty-codec-haproxyto a version that resolves this vulnerability.Fixed in 4.2.15.Final - Upgrade
Upgrade
netty-codec-haproxyto a version that resolves this vulnerability.Fixed in 4.1.135.Final - Upgrade
Upgrade
netty-codec-haproxyto a version that resolves this vulnerability.Fixed in 4.2.15.Final
Event History
Frequently Asked Questions
What is the severity of CVE-2026-44893?
CVE-2026-44893 has a high severity score of 7.5.
What are the risks associated with CVE-2026-44893?
CVE-2026-44893 could lead to an IndexOutOfBoundsException if the TLV length is set below 5.
How do I fix CVE-2026-44893?
To fix CVE-2026-44893, update to a patched version of the Netty library.
Which software is affected by CVE-2026-44893?
CVE-2026-44893 affects the maven/io.netty:netty-codec-haproxy module.
When was CVE-2026-44893 published?
CVE-2026-44893 was published on June 8, 2026.