Android’s Monthly security Patch is here for the month of January. It is available for Pixel and Pixel XL (NMF26U, NMF26V), Pixel C (N4F26I), Nexus 6P (N4F26I, N4F26J), Nexus 5X (N4F26I), Nexus Player (NMF26R), and Nexus 9 (N4F26M).
This security patch is packed with new security features to AOSP and new updates for the Pixel line and certain Nexus devices. However, security update is not the major update, But still it patches any potential exploits or vulnerabilities on your device. So its worth updating your device.
Google is rolling out the OTA to all the eligible phones. Meanwhile you can also manually update your devices by going through the source link below.
Source : Factory Images | OTA Files | Security Bulletin