(n.) The quality or state of being vulnerable; vulnerableness.

ad lib assailability breakability breakableness brittleness chink crackability crackableness crispness crumbliness crushability crushableness delicacy disqualification exposure extemporaneousness fissility flimsiness fracturableness fragility frailty frangibility friability heel of Achilles improvisation incapability incompetence lacerability lack of preparation liability nonpreparation nonpreparedness openness penetrability planlessness pregnability soft spot susceptibility susceptivity unfitness unfittedness unpreparedness unqualification unqualifiedness unreadiness unsuitability unsuitableness unsuitedness vincibility vulnerable point weak link weak point weakness