Following the launch of the Android Studio 2.1.1 update earlier in May, Google has begun contacting registered Google Play developers, advising them to upgrade to patch a security vulnerability present in prior versions.
Google is quick to note that the vulnerability in question is only present in the development environment itself and doesn't affect apps built in Android Studio. From Google:
As an app developer on Google Play, we wanted to make you aware of an important security update for Android Studio.
On May 11th, we released the Android Studio 2.1.1 update. This incremental update addresses a security vulnerability in the underlying IntelliJ platform that affects all previous versions of Android Studio. The vulnerability concerns the IDE itself and has no effect on individual apps.
If you develop in Android Studio and haven't yet updated, you should do so now. To manually grab the update, head to the Android Studio menu on OS X and tap "Check for Updates." On Windows, the option is listed under the "Help" menu. The latest Android Studio is always available as a direct download from Google as well.