In modern biological forms, it's not essential that water be present for DNA to have stability. There are other mechanisms that now exist in biology to accomplish that, and complex biological processes are possible that don't always require water. But in its most basic form, we now know that DNA bases are not stable and they are highly vulnerable to UV-induced damage.  -   Wei Kong     Quotes
In modern biological forms, it's not essential that water be present for DNA to have stability. There are other mechanisms that now exist in biology to accomplish that, and complex biological processes are possible that don't always require water. But in its most basic form, we now know that DNA bases are not stable and they are highly vulnerable to UV-induced damage. Wei Kong