Early Lease termination and security deposit

[Jay V.]

If tenant is terminating lease early and there is no past due rent or damages, can a landlord keep full or partial security deposit as a penalty for lease termination? Note a new tenant has been found and the old tenant helped with showings. There's a vague reference to it in lease contract for lease termination penalty, but not explicit. Morally it feels like it should be returned, but curious what others do.