CVE-2026-44893

Netty: HAProxy SSL TLV parsing leaks retained slice on invalid TLV length

HIGH
7.5
CVSS Score
Published: June 12, 2026 at 02:00 PM UTC
Updated: September 18, 2026 at 02:29 PM UTC
9 products affected across 2 vendorsNettyBuild of KeycloakFuse

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Severity
HIGH7.5
Exploit prediction
EPSS 0.6%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 4.1.135v < 4.1.135.Finalv < 4.2.15.Final4.2.0 ≤ v < 4.2.15
Affected range stops below 4.1.135, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.1.135.Final, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.2.15, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.2.15.Final, so it looks safe — our inference, not a vendor statement
All versions

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (22)

x_refsource_CONFIRMVendor Advisory
Source: cverecord
https://github.com/netty/netty/security/advisories/GHSA-cc37-9q2j-3hfv
x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/netty/netty/releases/tag/netty-4.1.135.Final
x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/netty/netty/releases/tag/netty-4.2.15.Final
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/errata/RHSA-2026:26017
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/errata/RHSA-2026:26018
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/errata/RHSA-2026:26586
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/security/cve/CVE-2026-44893
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://bugzilla.redhat.com/show_bug.cgi?id=2488383

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-703CWE-805

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