vulnerability

1. (uncountable) The state of being vulnerable; susceptibility to attack or injury, either physical or emotional; the state or condition of being weak or poorly defended.Examples: "The country recognized their defence vulnerability after an airplane landed in front of the central square without any consequences."; "Though scientists do not know how stress affects gestation, Fukuda theorizes that the vulnerability of Y-bearing sperm cells, male embryos and/or male fetuses to stress is why “subtle significant changes in sex ratios” occur."; "Again, voice change is not easy and vulnerability plays a big part, but if choral teachers and adolescent singers approach it with the right mindframe, the experience can be empowering, enlightening, and restorative for all involved."

2. (countable) A specific weakness in the protections or defences surrounding someone or something.

3. (computing) A weakness which allows an attacker to reduce a system's security.Examples: "Experts told CNN it could take weeks to address the vulnerabilities and that suspected Chinese hackers are already attempting to exploit it."