I built a tool that monitors commits and tries to detect silent bug fixes. With GPT-5.5-class models, it can identify fixes hidden within otherwise routine commits quite reliably. Obfuscating the code changes enough to avoid detection is difficult.
I have heard of at least one project (c-lightning?) temporarily releasing a closed-source binary as a workaround until users could update safely.
Have you heard of these things called LLMs are that are quite good at reversing changes in closed source binaries?