What is the ruling on one who does not acknowledge something forbidden in the religion, such as revealing a woman's foot as 'awrah (private parts)?

The forbidden acts, whose permissibility leads to disbelief, are those whose prohibition has been unanimously agreed upon and whose ruling has become manifest among Muslims, such that there is no room for interpretation or doubt. One who denies theawrah of a woman's foot does not become a disbeliever, because it is not known to be a necessary part of the religion. The same applies to all matters that are forbidden but are subject to dispute, and an ignorant person who denies such a matter does not become a disbeliever, even if they are mistaken.