Are you counting ones that involve running malicious code in a sandbox and not just trusted code on untrusted input? Because then I'd agree, but that's a much harder and different problem.

My impression is that for the trusted code untrusted input case it hasn't been that many, but I could be wrong.

It depends, what language was the sandbox written in?

Sandboxes are difficult independent of language, see all the recent speculation vulnerabilities for instance. Sure, worse languages make it even harder, but I think we're straying from the original topic of "python/ruby" by considering sandboxes at all.

How many ways to cause a segmentation fault in CPython, that don't start with deliberate corruption of the bytecode, are you aware of?

How is "type confusion" a security issue?