I manage multi user systems and try to be on top of this and no, privilege escalation with a working public exploit are very rare. There's quite a lot of CVEs with potential privilege excalation, but most of the time there is no real world exploit. And a large part of those are related to user namespaces in one way or another.

This one is truly scary, at least the immediate mitigation is pretty straightforward.

Well, it often feels like every "Linux security issue" flagged in the tech press is a privilege escalation, but I admit that I haven't sat down and done the math.