A flaw was found in Netty's HTTP/1 decoder. Incomplete validation of malformed Transfer-Encoding headers allows a remote attacker to perform HTTP request smuggling. By sending specially crafted HTTP requests, an attacker can inject arbitrary HTTP requests, potentially bypassing security controls or accessing unauthorized resources.
See https://github.com/netty/netty/security/advisories/GHSA-hcvj-94mj-jp5c for fixed versions and remediation guidance.