Looks like Rust to me.
Remove and destroy all leaves and plant parts affected by rust. You might have to destroy badly infected plants completely to prevent them infecting other plants of the same species. Spray with a suitable rust control product containing fungicide, repeating as recommended.
Blame the weather as it has been perfect for rust spores to spread.

I have just removed a ten year old Viburnum tinus 'Variegatum' as it was covered in rust. Sad to see it go.