A quick search of the ffmpeg commit history shows google has made plenty of contributions to ffmpeg. They may or may not provide a patch for this CVE but reporting it is the first step so people can then decide what action to take (like don't compile that codec in for example)

No, this is the unfortunate reality of “ffmpeg is maintained by volunteers” and “CVE discovered on specific untrusted input”.

Google’s AI system is no different than the oss-fuzz project of yesteryear: it ensures that the underlying bug is concretely reproducible before filing the bug. The 90-day disclosure window is standard disclosure policy and applies equally to hobby projects and Google Chrome.

I don't think Google is expecting anything here.

They run Big Sleep to find security vulnerabilities in projects they care about. It seems -- mostly from reading this issue's details -- that the finding is pretty high quality. Once a vulnerability is found, there's a duty to disclose the existence of the vulnerability to the project maintainers and, eventually, to the public within a reasonable timeframe.

The alternatives here are: not searching for the vulnerabilities in the first place; keeping the knowledge of the vulnerability secret; or notifying the public without the project maintainers having the opportunity to fix the vulnerability first. All of these are worse.

It's unlikely that Google cares about a vulnerability like this -- ffmpeg is probably run sandboxed and probably with a restricted set of codecs. So they're unlikely to spend engineering resources fixing it.

The project maintainers are under no obligation to actually fix the bug. The deadline is simply that the vulnerability will eventually be made public, even if it is not fixed. That's standard responsible disclosure and, again, is better than the alternatives.

You think google uses ffmpeg for youtube?