Description
Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.136.Final and 4.2.16.Final, Netty's HAProxy encoder ( HAProxyMessageEncoder ) writes AF_UNIX source and destination socket addresses into the HAProxy V1 text protocol without validating them for CRLF characters, so an attacker who controls an AF_UNIX address can inject  \r\n  sequences and split the single PROXY header into multiple lines. This is possible because the V1 protocol uses CRLF as its line terminator and, unlike IPv4/IPv6 addresses whose format checks implicitly reject CRLF, AF_UNIX addresses are only validated for length (up to 108 bytes), allowing a forged second PROXY header line that spoofs the client source/destination IP to a downstream server or load balancer. The issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
Published: 2026-07-29
Score: 5.5 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-wh89-7897-x99h Netty: HAProxy V1 Protocol CRLF Injection via AF_UNIX Address
History

Wed, 29 Jul 2026 18:15:00 +0000

Type Values Removed Values Added
Description A flaw was found in the netty-codec-haproxy component, part of the Netty network application framework. This vulnerability allows a remote attacker to perform protocol-level injection attacks by crafting malformed HAProxy protocol frames that contain embedded carriage return (CR) and line feed (LF) sequences. This can lead to the injection of arbitrary content, potentially disrupting network communication or enabling further attacks. Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.136.Final and 4.2.16.Final, Netty's HAProxy encoder ( HAProxyMessageEncoder ) writes AF_UNIX source and destination socket addresses into the HAProxy V1 text protocol without validating them for CRLF characters, so an attacker who controls an AF_UNIX address can inject  \r\n  sequences and split the single PROXY header into multiple lines. This is possible because the V1 protocol uses CRLF as its line terminator and, unlike IPv4/IPv6 addresses whose format checks implicitly reject CRLF, AF_UNIX addresses are only validated for length (up to 108 bytes), allowing a forged second PROXY header line that spoofs the client source/destination IP to a downstream server or load balancer. The issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
Title io.netty/netty-codec-haproxy: Netty: Improper CR/LF neutralization in netty-codec-haproxy Netty: HAProxy V1 Protocol CRLF Injection via AF_UNIX Address
References

Tue, 28 Jul 2026 00:15:00 +0000

Type Values Removed Values Added
Description A flaw was found in the netty-codec-haproxy component, part of the Netty network application framework. This vulnerability allows a remote attacker to perform protocol-level injection attacks by crafting malformed HAProxy protocol frames that contain embedded carriage return (CR) and line feed (LF) sequences. This can lead to the injection of arbitrary content, potentially disrupting network communication or enabling further attacks.
Title io.netty/netty-codec-haproxy: Netty: Improper CR/LF neutralization in netty-codec-haproxy
Weaknesses CWE-93
References
Metrics threat_severity

None

 cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N'}

threat_severity

Moderate

Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-07-29T18:06:11.495Z

Reserved: 2026-07-07T18:20:06.125Z

Link: CVE-2026-59919

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-07-09T00:00:00Z

Links: CVE-2026-59919 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses