Good call, pierino! ;o)

Fresh mozzarella or low moisture? Crucial difference. The former will get way skanky over 7 hours without refrigeration. As in it's going to begin to ferment in a not so pleasant way. Would you drink milk that you left out for seven hours?

It should be fine, though the cucumbers may not as crispy/crunchy as they would be if you'd refrigerated it. This assumes that ambient temperature is rather moderate, i.e., wasn't above 90 degrees. ;o)