A flaw was found in Netty's HTTP/1.1 decoder. This vulnerability allows a remote attacker to bypass Transfer-Encoding header validation by splitting the Transfer-Encoding field across multiple headers, with the last field containing a non-final transfer coding like gzip or deflate. This bypass can lead to HTTP request smuggling, enabling attackers to bypass security controls, desynchronize request processing, or cause requests to be processed in an unintended context.
See https://github.com/netty/netty/security/advisories/GHSA-3jrc-fchc-59pw for fixed versions and remediation guidance.