How to find your patch level.
The Security Patch Level can only be found on devices running Android Marshmallow.
The good news for Android Marshmallow (6.0) users is that the release includes very important improvements that go a long way to protect your device. One addition allows you to quickly find out the security patch level on your smartphone or tablet. It all started with the Stagefright vulnerability. Once the dust settled from that disaster, Google (and Samsung) made a promise to start rolling out monthly security updates. To that end, they decided to include a field in the device settings that would list for users to see when the last security patch was applied to the operating system.