A flaw was found in Netty. A reference-count leak in the HAProxy PROXY-v2 message decoder allows a remote, unauthenticated attacker to send specially crafted PROXY-protocol v2 headers. This can lead to memory exhaustion, resulting in a Denial of Service (DoS) for the affected system.
See https://github.com/netty/netty/security/advisories/GHSA-j58c-g352-8h4p for fixed versions and remediation guidance.