Google today began rolling out the May security patch to both Pixel and Nexus devices. once again, there are two different security patch levels rolling out: one labeled 2017-05-01 and the other 2017-05-05. Each has their own set of bug fixes but combined they resolve a hefty 118 different software vulnerabilities discovered over the last month. The most severe of these security holes happens to be a remote code execution vulnerability within Mediaserver.
You can download factory images of the May security patch for your device here, while OTA images are downloadable here. Those without a Pixel or Nexus device will likely still get this month’s security patch, but it could be awhile before that time comes.