Vulnerability

A vulnerability is a weak spot. A window that does not lock. A password anyone could guess. Software the maker fixed two years ago that nobody ever updated.

A weak spot is not automatically a problem. It depends on two things: can anyone actually get at it, and would it matter if they did? An unlocked window on the fourth floor of an empty building is not the same as an unlocked window at the front of a jeweller's. Treating every weak spot as equally urgent is the quickest way to miss the ones that are.