NetBSD team announced 7.1.1 release on 22 of December, 2017. It is security/critical update for NetBSD 7.1 branch. Download mirrors can be found here. Preferred way to download ISO and USB disk images is using torrent files. Finally file hashes can be verified in this location. Release announcement and changes can be found here and here. It is highly recommended to update your system if you are using 7.1 branch.