Is accusing a married woman of adultery, whether she is a Muslim or a disbeliever, considered one of the major sins in Islam?

It is not permissible to accuse a chaste disbelieving woman of adultery. Accusing her of such is considered a minor sin, and its perpetrator is subject to disciplinary punishment (ta'zir). However, it is not categorized among the major sins and does not necessitate the prescribed punishment (hadd) for the accuser. This is because Allah mentioned faith as a condition in the verse concerning accusation (qadhf), and chastity (ihsan), which is a condition for the implementation of the prescribed punishment, requires Islam.