Today Apple released macOS 10.13.5, a major software update to macOS High Sierra. Update any supported system using the built-in Software Update functionality through the Mac App Store, or by using the standalone installer available from Apple.com.
Download the macOS High Sierra 10.13.5 Update
Be sure to back up any important data, and if possible clone your hard drive before applying the update. If you have any issues post-update, press spacebar, and boot using Safe Mode.
What we know about 10.13.5 so far...
macOS Build 17F77
Updated apfs.efi- download here
This update will replace your audio drivers. If you enabled Realtek onboard audio using MultiBeast or the cloverALC script, no changes will be necessary.
Install macOS High Sierra App has been updated - If you downloaded macOS High Sierra from the App Store prior to today, and you want to have the latest version on your backup installer USB, simply log into the Mac App Store and click Download. The updated Install macOS High Sierra App can be found in the Applications folder.
Testing is now underway- this post will be updated. Good luck, and let us know how it goes! Report your results here.