An online service is a program (or a bunch of program).

Giving access when it’s not supposed to falls into behaving in a way that’s not intended.

Therefore, an online service giving access when it’s not supposed to can be classified as a program behaving in a way that’s not intended.

Thus, this case fits into your very definition.

It also illustrates how a security vulnerability is simply a bug, albeit a dangerous one.

CNN as in “Central News Network” or “Convoluted Neural Network”?

Would I have to say yes if I let my wife roam cage free?