I dont think that will ever be possible.
At some point security becomes - the program does the thing the human wanted it to do but didn't realize they didn't actually want.
No amount of testing can fix logic bugs due to bad specification.
Well, yes, agreed - that is the essential domain complexity.
But my argument is that we can work to minimize the time we spend on verifying the code-level accidental complexity.
AI as advanced fuzz-testing is ridiculously helpful though - hardly any bug you can in this sort of advanced system is a specification logic bug. It's low-level security-based stuff, finding ways to DDOS a local process, or work around OS-level security restrictions, etc.