Does a woman sin if she marries during a period of an invalid marriage?

A vitiated marriage is not permissible to continue, and it has two cases: 1. That whose vitiation is disputed: Such as a marriage contracted without a guardian (wali) or without witnesses. This requires annulment (faskh (definition)) or divorce (talaq (definition)) according to most scholars before marrying another. 2. That whose vitiation is agreed upon: Such as marrying a fifth wife or a woman undergoing her 'iddah (definition) (waiting period). This does not require annulment or divorce, and the woman is permitted to marry another person directly, because the first marriage is considered non-existent.

The Hanbalis view that a "vitiated marriage" (نكاح فاسد) is one whose vitiation is disputed (like a marriage without a guardian), while a "void marriage" (باطل) is one whose vitiation is agreed upon (like marrying a fifth wife or a woman in her 'iddah).