Today, AI can be pointed at an open source codebase and systematically scan it for vulnerabilities.

AI also goes a long way towards erasing the distinction between source code and executable code. The disassembly skill of a good LLM is nothing short of jaw-dropping.

So going closed-source may be safer for SaaS, but closing the source won't save a codebase from being exploited if the binaries are still accessible to the public. In that sense, instead of dooming SaaS as many people have suggested AI will do, it may instead be a boon.