CVE-2026-59900: Inconsistent Interpretation of HTTP Requests

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...

netty: possible request smuggling in HTTP/2 due missing validation

In Netty io.netty:netty-codec-http2 before version 4.1.60.Final there is a vulnerability that enables request smuggling. If a Content-Length header is present in the original HTTP/2 request, the field is not validated by Http2MultiplexHandler as it is propagated up. This is fine as long as the...

CVE-2021-21295

Netty is an open-source, asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. In Netty io.netty:netty-codec-http2 before version 4.1.60.Final there is a vulnerability that enables request smuggling. If a...

PT-2021-5814

Name of the Vulnerable Software and Affected Versions io.netty:netty-codec-http2 versions prior to 4.1.60.Final Description The issue is related to the handling of HTTP/2 requests in the Netty framework, specifically when the Content-Length header is present. If a request comes in as an HTTP/2...