While the mobile carriers in the US are sending Android Pie for Galaxy Note 8, the same device around the world, which has been already updated on the latest OS update is now started receiving the latest security update.
This update for Galaxy Note 8 brings April 2019 security patch that provides fixes to 15 new Samsung Vulnerabilities and Exposures items found in the recent software version.
One UI: Ultimate Tips, Tricks and How To guide for new features
The build version for this update is - N950FXXS5DSC5 and it's currently rolling in Russia, Netherlands, Italy, Germany and more. If you want to check the update manually please go to the Settings > Software update > Download and install.