There is a very nasty bug that effects ALL WiFi devices. There are patches in the works for most devices (all current iOS Devices, Windows 7, 8 and 10, Current Android devices). If you use a device that’s not supported anymore (Old Android phones, Old iPhones etc) then these will not be patched.Windows 10 had a patch out last week for it, Apple is testing a patch now and Google are doing the same. If you have an Android phone that is not made by Google then your manufacturer will also have to test the patch after google has tested it.
Until the patch is released, use only the official apps for banking as they encrypt the data before it leaves the device.
Make sure you use the “HTTPS” function on any website that needs a password as again that has end to end encryption.
If you use a VPN then your data is also safe.
DO NOT USE ANY PASSWORDS THAT ARE SENSITIVE on any sites that do not use any encryption, and assume ALL your data over WiFi is out in the open and anyone with technical knowledge can read it.