If the vegetables have been cut and then left out overnight or longer than 2 hours then it's not recommended to eat the vegetables left out.
When vegetables are left out overnight or longer than 2 hours they can have bacteria that grows rapidly on them even though you may not be able to see them.
Same goes for canned vegetables or other vegetables such as green beans, peas, corn etc that has been left out longer than 2 hours it would not be the best thing to do to eat the food.
It's really not worth the risk but you would likely just get food poisoning that would not be severe but I still would not chance it.
Always put any leftover vegetables in the refrigerator or freezer to prevent bacteria from growing on them.