I am twice-divorced. Do I have to get special dispensation to become a Catholic?
If you are not currently married or living in an extramarital relationship, no. Should you decide that you would like to marry again or to enter religious life, then you would have to put your marriages before the marriage tribunal for a decision.
If you are currently married, you will need to get your marital situation regularized before you can be received into the Church. If you and your husband are willing to observe celibate chastity until the tribunal process is complete, you can be received into the Church before an annulment is granted.
Annulments and the Catholic Church** by Edward Peters