Google has posted the official images for the August Security Patch for Pixel and Nexus devices, which means that likely starting today or tomorrow and progressing though the rest of the week, users are going to start getting updates to this patch officially over-the-air. In the mean time, anyone who doesn't want to wait for the patch to come through to their devices in the official manner can always flash the images that Google has now provided as it is the same software, it merely requires more effort on the part of the user than simply tapping a button that says "update."
That being said, if you're looking to install the software patch from Google on your own, it is worth mentioning that doing so should only be done if you're familiar with the process. It's not overly challenging but steps do need to be followed correctly. Luckily for anyone that isn't familiar with the steps to follow, Google has all the instructions for flashing listed with each type of patch download so you'll have everything you need to complete the update. If you're planning on moving forward with installing the latest security patch on your own, there are two types of the update which can be installed, though they are exactly the same in the end.
Both the Factory Images and the Official OTA Images are available now in the Downloads section of Google's APIs for Android website, and you can grab each version of the software from the buttons below. As for the devices which have this patch available for download, this includes the Pixel and Pixel XL, as well as the Nexus 6P, Nexus 5X, Pixel C tablet, Nexus Player, and both the Wi-Fi and LTE versions of the Nexus 9 tablet. Unfortunately support for security updates stops here when it comes to Google's Nexus devices as anything older than the Nexus 9 is past the shelf life for update support. As for non-Google devices, the security patches will come in their own time from their respective carriers and OEMs, as they always do, so users of such devices will still need to wait a bit longer to get their hands on the latest security fixes.