Known Vulnerability CVE-2019-10797 when Using Netty 3
When using Netty 3 there is a known vulnerability (CVE-2019-10797 according to NIST) and the solution and workaround is to use Netty 4.
In other words, the known vulnerability (CVE-2019-10797) does not affect you if you are using Netty 4.
To be backward compliant in terms of performance requirements, it is not feasible to remove Netty 3 from MediationZone at this point.