CVE-2026-44893: Netty: HAProxy SSL TLV parsing leaks retained slice on invalid TLV length

Published Jun 8, 2026
·
Updated

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

5 affected componentsFixes available
maven/io.netty:netty-codec-haproxy<=4.1.134.Final
4.1.135.Final
maven/io.netty:netty-codec-haproxy>=4.2.0.Final<=4.2.14.Final
4.2.15.Final
Netty Netty<4.1.135
Netty Netty>=4.2.0<4.2.15
IBM Netezza Software<=11.3.0.3-IF2

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade maven/io.netty:netty-codec-haproxy to a version that resolves this vulnerability.

    Fixed in 4.1.135.Final
  2. Upgrade

    Upgrade maven/io.netty:netty-codec-haproxy to a version that resolves this vulnerability.

    Fixed in 4.2.15.Final
  3. Upgrade

    Upgrade netty-codec-haproxy to a version that resolves this vulnerability.

    Fixed in 4.1.135.Final
  4. Upgrade

    Upgrade netty-codec-haproxy to a version that resolves this vulnerability.

    Fixed in 4.2.15.Final

Event History

Jun 8, 2026
Advisory Published
via GitHub·07:02 PM
Data Sourced
via GitHub·07:02 PM
DescriptionSeverityAffected Software
Data Sourced
via GitHub·07:02 PM
Weakness
Jun 12, 2026
CVE Published
via MITRE·02:00 PM
Data Sourced
via MITRE·02:00 PM
DescriptionSeverityWeakness
Data Sourced
via Red Hat·03:01 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·03:16 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·03:16 PM
Affected Software
Aug 20, 2026
Data Sourced
via IBM·12:00 AM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Frequently Asked Questions

1

What is the severity of CVE-2026-44893?

CVE-2026-44893 has a high severity score of 7.5.

2

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.

3

How do I fix CVE-2026-44893?

To fix CVE-2026-44893, update to a patched version of the Netty library.

4

Which software is affected by CVE-2026-44893?

CVE-2026-44893 affects the maven/io.netty:netty-codec-haproxy module.

5

When was CVE-2026-44893 published?

CVE-2026-44893 was published on June 8, 2026.

Contact

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