My co-op has a default foreclosure judgement and the apartment has been auctioned. Any recourse? Can I reverse the default judgement?

Thanks

Short answer: no.

Longer answer: we would need to know more information. Such as:

what is your relationship with this co-op?
the co-op owned the apartment, a default judgment of foreclosure was taken against the co-op, and the property was sold?
are you residing in the apartment?
which state or country are you in (that nearly always is important)?