This is what I have been told:

While the judgement is against the individual, it clouds title on any real estate that person owns in the same county of record. If you buy the house, the judgement issue will still exist and you won't have good marketable title to the property.

I think the judgements disappear after 10 years unless the creditor renews the judgement at the 10 year mark. If the judgment is small, maybe you could negotiate with the creditor in advance.