Google has just released the March security patch for its current Pixel and Nexus devices. This is for devices that have officially been updated to the Android v7.1.1, carrying the build number NOF27B.
The patch officially brings VoLTE support to the handsets with certain carriers (build NOF27C), apart from that it addresses multiple bugs and vulnerabilities. The most severe of these vulnerabilities allow remote code execution while browsing, using email or accessing MMS, although Google reassures that there are no reports of customers having been affected by these issues. The patch also improves the reliability of using the Bluetooth standard for sending and receiving messages, calls. For a complete breakdown of these changes please refer to the security bulletin, here.
Google devices should have started receiving this update OTA (over the air) as of writing this article and have official sources to directly download the images. You can also download the complete factory images for Nexus / Pixel devices, here. Other major OEM’s and manufacturers should provide this update for their devices with device-specific fixes shortly.