23 Oct 2026 15:48:27 UTC
Netty: HTTP Header Injection via HttpProxyHandler Disabled Validation
cve-program · CVE-2026-42578 · Published
CVE-2026-42578
Netty: HTTP Header Injection via HttpProxyHandler Disabled Validation
CVSS 4.0 2.9 LOWCheck source for fixed versionsKEV status unknown
cve-program · CVE-2026-42578
PublishedNetty 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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