I would be uncomfortable with that. But that's just me. In reality, CPUs can function perfectly with no problems above that. If the CPU is not activating thermal protection modes out of self preservation, there probably is no harm - at least not immediate harm. But long periods of high heat can increase aging. And it can also affect surrounding components. So I would still want to look at case cooling. And if necessary, even going for a more efficient aftermarket CPU cooler.