Release Notes
https://suricata-ids.org/2017/07/27/suricata-4-0-released/
Redmine tracker
https://redmine.openinfosecfoundation.org/versions/101
Download
https://www.openinfosecfoundation.org/download/suricata-4.0.0.tar.gz
https://www.openinfosecfoundation.org/download/suricata-4.0.0.tar.gz.sig