Google just posted the Android security update for September 2017 and the files are already live for a number of devices, both Pixel and Nexus.
So far, we are seeing 8.0.0 files for Pixel and Pixel XL (OPR1.170623.026, OPR3.170623.007), Pixel C (OPR1.170623.026), Nexus 6P (OPR6.170623.017), and Nexus 5X (OPR4.170623.006).
We’ve also got new 7.1.1 files for Nexus 6 (NGI55D) and Nexus 9 (N9F27L, N4F27O).
The notes here for each Pixel update indicate that OPR1.170623.026 is for Project Fi and Canada models, while OPR3.170623.007 must be for everyone else.
You can grab each image or OTA file at the links below. For instructions on how to flash a factory image, here you go. For instructions on how to flash an OTA .zip file, here you go.
As more files arrive, we’ll update this post.
UPDATE: Nexus Player Oreo files are now up.