Google accidentally pushed an internal Android build, intended only for use by the company's employees, to an unknown number of Pixel XL handsets.
Multiple owners of the device - including Android Police founder Artem Russakovskii - received a notification on their handsets, clearly marking the update as "CONFIDENTIAL INTERNAL ONLY", and further emphasizing that it was a "confidential Googlers-only OTA". It also warned those who were intended to install it to "not discuss or comment on this update externally."
The update - which bumped up the Pixel XL's build number to N2G47O - left the Android OS version unchanged at 7.1.2, but included the May 2017 security patches, weeks ahead of their public release. The most recent monthly security update for Android was published just over two weeks ago.
This isn't the only incident involving Google's OTA updates in recent weeks. Last month, a number of Nexus 6 owners were prompted to install Android 7.0 after receiving the delayed Android 7.1.1 update on their handsets, causing severe usability issues. And last week, numerous owners of Google's Pixel and Nexus devices reported problems with their fingerprint sensors after installing the latest public Android 7.1.2 build.
Source: Android Police