Sony has released a software update for their Sony Xperia XZ Premium handset and the update comes with the version number 45.0.A.7.90.
The software update for the Sony Xperia XZ Premium comes with the latest security patch from Google for their Android OS.
The update features the July security patch for Android and it fixes a number of vulnerabilities in Google’s Android OS.
The software update for the Sony Xperia XZ Premium has been released as an over the air update and should be available for your device as of now.
Source Xperia Blog