The Mazda CX-5 and Hyundai Tucson share a hub bore of 67.1mm and a bolt pattern of 5 x 114.3 with M12 x 1.5 threads, so theoretically the space saver from your Mazda will fit the Hyundai, but the offset is slightly different, so if you do need to use it it would be wise to get the original tyre repaired as soon as possible.