It feels like the only solution is going to be proactively running your own AI agents looking for patches and applying them.
Prompting the LLM to "look for vulnerabilities in PHP's multipart upload handling code" is going to find stuff that "look for vulnerabilities in PHP" won't.
Those can leak / be stolen of course, but a bunch of my clients php apis survived as without a cert they’re told to fuck right off.
It does make their client onboarding a bit harder but it’s a trade off which seems to have been the right one.