It's wasn't the undefined-ness of the overflow that was the problem here - the bugs would have been exactly the same if 2s complement wrapping overflow had been

It's wasn't the undefined-ness of the overflow that was the problem here - the bugs would have been exactly the same if 2s complement wrapping overflow had been mandated. So these would still have been bugs under the JVM too - crashing from an out-of-bound array access or failing to allocate a stupendously large number of objects. The JVM would stop them from turning into potential arbitrary code execution, though (as some, but not all, of these bugs did).