No, but if you don't patch them you need to convince an auditor that they are not a problem. Often patching is easier.

I'm working on such a problem now - we are using an old web browser (no longer supported) to show help on one system. That is web pages were generate internally, with no links elsewhere, and no provision for the user to enter a URL. It is still easier port to a newer supported browser than to convince the auditors that that we are not exploitable. Sure it is obvious that everything is internal and we won't write html that exploits bugs, but nobody wants to convince an auditor of that.