New factory images for build LMY48I has been posted by Google, which contains fixes for the Stagefright security exploit, for several Nexus devices. In all, the new build is available for the Nexus 4, Nexus 5, Nexus 6, Nexus 7 (2013, WiFi), Nexus 9 (LTE and WiFi), and Nexus 10.

Today in a blog post, Google said the update would roll out a new monthly security update schedule for Nexus devices, and the build number is in line with earlier reports from Sprint about the rolling out to the Nexus 5 and Nexus 6.
If you’re interested in updating your Nexus device to the latest build manually, you’ll find links from Google for each device receiving LMY48I at the link below. If you find the process complicated then check out the guide given by guys at androidcentral.
Download the latest factory image for your Nexus device