You may we have heard over the weekend that there’s a Visa security issue within Apple Pay. It’s only related to Visa cards that are set to use Apple Pay Express Travel. Apple and Visa can’t agree who needs to fix the issue at the moment, but the good news is that this feature can easily be switched off. It’s recommended that you do this until it’s patched.
See Apple’s Express Travel support page here. BBC’s in depth article here.