Wiktionary
breachable
a. That can be breached; vulnerable.
Usage examples of "breachable".
The stone wall that encircled the two dozen or so buildings was breachable if a trespasser was determined, but sleepy Mistledale would hardly be worth the effort There was only one major street, which wound haphazardly through the town.
Dara began, pausing to consider her words carefully, "It has been my opinion for some time that the computer security protocols, as well as the command codes themselves, are breachable.
Then the Laagi ships would withdraw from an assault against a Frontier line that well over a hundred years of fighting had taught was permanently un breachable by either side.