Sony Mobile has updated the Xperia XZ2 moving the build number from 51.1.A.4.265 to version 51.1.A.11.26. This latest update includes the 1 August 2018 Android security patches. The Xperia XZ2 Compact has not been updated at the time of writing, but it should follow shortly. If you have updated do let us know of your impressions in the comments below.
Thanks Abdula!