There’s a bad new bug out there called Krack. It allows interception of WPA-protected Wifi traffic. That’s what your phone is using, as well as your router, and practically every other wireless device in your house.
First of all, don’t panic. If you have a secure password on your router, then it’s going to be tough to get to your devices. Hackers will have to be within range of your wireless signal, in other words parked outside your house. But do update every device in your home that you can, as soon as updates are available.
That being said, you might consider not using Wifi on your phone outside of your house. At Starbucks, for instance. A hacker could set up there and look at traffic on dozens of phones a day.
Another thing that protects you is that most websites encrypt their traffic, so any credentials you send can’t be read anyway.
So don’t freak out. Update every device you can. Stop using public networks until your phone is fixed (it may take months for its update to become available). And make sure your home router has a tough password.