What is the ruling on zinā committed by an un-muḥṣan individual who has never been married, with a muḥṣanah, a widow, a divorcee, or a married kāfirah?

Adultery (zina) is one of the gravest major sins. Allah has coupled His warning against it with polytheism (shirk) and taking a life, and He has forbidden even approaching it. It is defined as a man and a woman engaging in sexual intercourse outside of a lawful marital relationship. Adultery is forbidden for both the married (muhsan) and the unmarried, with any woman. Adultery with a married woman is more strictly forbidden and a greater sin due to the violation of the husband's sanctity, the corruption of his bed, and the attribution of lineage to him.