This Shit is Hard: Patching a vulnerability that has no fix

The standard advice for handling a vulnerability is comfortingly simple: wait for the upstream maintainers to ship a fix, then apply it. It's good advice. It's also completely useless when there is no fix. That's the situation we build for behind Athena, our vulnerability clearinghouse. Athena works with zero-days that frontier AI models surface, and models are now finding serious, exploitable flaws far faster than maintainers can patch them. For the overwhelming majority of these findings, there is no upstream commit to backport, no maintainer to defer to, and no reference fix to trust. Our starting point is a validated, exploitable vulnerability, an embargo clock, and a question: who is going to fix this? At coalition scale, the answer must be automation. And that turns out to be a genuinely hard engineering problem, not because getting an AI to write a diff is hard. That part is trivial. It's because everything you'd normally lean on to trust that diff is gone. The previous post in this series covered where this dangerous work runs. We use a microVM sandbox that lets us treat every job as a controlled detonation. Today’s post talks about what work happens inside that sandbox. We've written…