Not so. I had a married couple as RCIA students (adults wanting to enter the Catholic Church) who both had previous marriages. They've been married (civilly) for 10 years. When they sought to enter the Church, they had to resolve their situation by seeking annulment from their previous attempted marriages. It took awhile, but they did it. The entered the Church last Easter. And they just had their marriage to each other--- their present, and only real marriage ---"covalidated" in a short, simple 10-min. ceremony with our pastor at a weekday morning Mass. It was sweet.
On the other hand, if the previous marriages were judged valid, they can't canonically be married to each other. It is bigamy to be married to a second person while your first spouse is still living.
What is an “attempted marriage”? I always thought that was something like the groom getting run off the altar by an angry dad with a shotgun.
Not ten years later, when the couple has had 5 kids.