The SslHandler in Netty before 3.9.2 allows remote attackers to cause a denial of service (infinite loop and CPU consumption) via a crafted SSLv2Hello message.
https://lists.debian.org/debian-lts-announce/2020/02/msg00018.html
https://github.com/netty/netty/commit/2fa9400a59d0563a66908aba55c41e7285a04994