A flaw was found in Netty's HTTP/2 HpackEncoder. A remote attacker can exploit this by sending HTTP/2 SETTINGS frames with a very large MAX_HEADER_TABLE_SIZE. This causes the HpackEncoder to store an excessive number of unique headers, leading to increased CPU usage and memory consumption, ultimately resulting in a Denial of Service (DoS).
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.