Keeping up with the Monthly Security updates, Google has just released the security bulletin for the April 2016 update. Samsung and Verizon actually beat Google to rolling out this update, and pushed it out to the Galaxy S6 and Galaxy S6 Edge last week. And now all those with Nexus devices that are still being updated, are going to be getting the update in the coming days. Nexus devices that are still getting security patches include the Nexus 5, Nexus 5X, Nexus 6, Nexus 6P, Nexus 7 (2013 WiFi and LTE), Nexus 9 (WiFi and LTE), Nexus 10, and the Nexus Player. The Pixel C is also getting updates, but it's not technically a Nexus device. The Nexus 10 is the only device of those listed above that is not on Marshmallow, so it's nice to see it getting security updates still.
This security patch that's rolling out has quite a few critical patches in the update. We heard last month that there would be a second security update for the month of March, but we never received it. It looks like the issues that were fixed in that update are now in the April patch, as you'd expect (and as Google had originally planned). There are 6 "critical" issues that were fixed, and four of those involved remote code for different parts of the OS including the MediaServer. Along with about 13 "high" issues that were resolved here. If you want to get into the full nitty-gritty of what has been patched in this update, head to the source link below.
As usual with Google, they are not going into full detail on these vulnerabilities, and with good reason. This is to protect devices that have not received the patch yet. If they detail these vulnerabilities, someone could use them to get into your phone and do all sorts of things. So this is to protect users. As we know security updates aren't quick, when it comes to non-Nexus devices, and devices that are carrier branded. So this is definitely an important thing for Google to do. For instance, some Galaxy Note 5's are still sitting on a November 2015 patch, which is now 6 months out of date.
The factory images are now up for the April security patch, and the OTA should begin rolling out in the next few days for those with the Nexus 5, Nexus 5X, Nexus 6, Nexus 6P, Nexus 7 (2013), Nexus 9, Nexus 10, Nexus Player and the Pixel C.