If you have been living under a rock and are not aware of what stage fright is, it is essentially a vulnerability in Android which allows a hacker to send a certain Video file via text message which gives them full access to your device. OEMs have been frantically racing to get the patch out to handsets. Google has finally released the patch for Nexus devices. You can check for an OTA update. The updates roll out in batches so if you don't have the update you can grab the image and flash it manually. Grab the image for your device from the link below.
via Google