The second security patch for ArcGIS Server in 2016 was released in May, and now the second security patch of Portal for ArcGIS in 2016 is being released (hence the name 2016 Update2). We recommend our customers apply this patch in a timely manner. To be clear, there are separate security patches for ArcGIS Server and Portal for ArcGIS, and both should be applied if you are utilizing the applicable software/versions. These updates have already been incorporated into 10.4 and later releases of Portal for ArcGIS, so it is necessary for just prior releases.
– The Security Standards & Architecture Team
Portal for ArcGIS Security 2016 Update 2 Patch – Available for 10.3.1 and 10.2.2