The canonical status of someone married outside the Church is that they are in an irregular marriage and thus cannot receive communion. However once they divorce they have ended their irregular status and the external violation of Church law no longer exists. At that point all that’s left is to deal with the internal forum, i.e. their spiritual life. An individual in that situation, while externally being able to receive communion, still needs to make a good confession and right their spiritual life so that they might worthily receive communion.
