CVE-2026-59900 Netty codec-http2: Lack of Host Header Deduplication in HTTP/2→HTTP/1.x Translation Leads to Request Routing Bypass

Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.136.Final and 4.2.16.Final, Netty's HTTP/2-to-HTTP/1.x translation layer Http2StreamFrameToHttpObjectCodec and InboundHttp2ToHttpAdapter fails to deduplicate or validate Host headers when an HTTP/2 client...