Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty's HttpProxyHandler constructs HTTP CONNECT requests with header validation explicitly disabled. The newInitialMessage() method creates headers using DefaultHttpHeadersFactory.headersFactory().withValidation(false), then adds user-provided outboundHeaders without any CRLF validation. This allows an attacker who can influence the outbound headers to inject arbitrary HTTP headers into the CONNECT request sent to the proxy server. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

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Vendors Products
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-45q3-82m4-75jr Netty has HTTP Header Injection via HttpProxyHandler Disabled Validation (Incomplete Fix CVE-2025-67735)
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 13 May 2026 20:00:00 +0000

Type Values Removed Values Added
First Time appeared Netty
Netty netty
Vendors & Products Netty
Netty netty

Wed, 13 May 2026 18:30:00 +0000

Type Values Removed Values Added
Description Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty's HttpProxyHandler constructs HTTP CONNECT requests with header validation explicitly disabled. The newInitialMessage() method creates headers using DefaultHttpHeadersFactory.headersFactory().withValidation(false), then adds user-provided outboundHeaders without any CRLF validation. This allows an attacker who can influence the outbound headers to inject arbitrary HTTP headers into the CONNECT request sent to the proxy server. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
Title Netty: HTTP Header Injection via HttpProxyHandler Disabled Validation
Weaknesses CWE-113
References
Metrics cvssV4_0

{'score': 2.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-13T18:37:18.204Z

Reserved: 2026-04-28T17:26:12.085Z

Link: CVE-2026-42578

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-05-13T19:17:23.210

Modified: 2026-05-13T19:17:23.210

Link: CVE-2026-42578

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-13T19:45:03Z

Weaknesses