Your safety is my priority so I give you this information as fast as possible:
There is a gap in iOS security which can be used by hacker to take over control under device.
We are talking about all systems based on iOS - iOS, watchOS, tvOS and OSX. So it's high priority to update your OS as fast as possible.
Cisco Talos's specialists informed about it some time ago.
Source: gsmmaniak (polish)