NetSight
IP …
high7.5

CVE-2026-42578

Netty has HTTP Header Injection via HttpProxyHandler Disabled Validation (Incomplete Fix CVE-2025-67735)

Impact

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.

Affected packages

EcosystemPackageAffectedFixed in
mavenio.netty:netty-handler-proxy<= 4.1.132.Final4.1.133.Final

Affected products

VendorProductAffected versions
NettyNetty
before 4.1.133
from 4.2.0 before 4.2.13

Weakness classification

CWE-113CWE-93

References