If a person divorces for legitimate reasons and does not marry someone else (unless the first marriage is declared null), then there is no sin and the person may receive the Eucharist.
That’s what I was always taught in Catholic school. Of course, we Catholics were attacked for not allowing the divorced to remarry in the Church. You can’t win for losing!
Who determines "legitimate reasons"? Far as I know, the Bible says only adultery is "legitimate". The catholic "church" says otherwise.