Is tenant legally required to pay rent if the owner of the house is in default?

Generally speaking, as long as the landlord has legal control over the property, the rent is still due him and he may continue collecting it. However, most Housing Authorities prohibit landlords from becoming in default of their mortgage. Generally speaking, if the Housing Authority tells you to continue to pay your rent, you must do so or risk eviction- And possibly the loss of your voucher.