Version 3.5.0.0 is available upstream. Please consider updating! It seems that version 3.5.0.0 is available upstream, while the latest version in the Gentoo tree is 2.9.20. You think this warning is false? Read more about it here.
Snort is an open source network intrusion prevention and detection
system (IDS/IPS) developed by Sourcefire. Combining the benefits of
signature, protocol, and anomaly-based inspection, Snort is the most
widely deployed IDS/IPS technology worldwide. With millions of downloads
and approximately 300,000 registered users, Snort has become the de facto
standard for IPS.