There's no such thing as a CMS without templates. Even no template at all ... is technically a template.
And if you really want to get theoretical, there is no such thing as a website without a template. At the very least, the layout of your index.html file, coupled with your CSS styles ... constitutes a "template."
If you're talking about using a CMS without a "pre-made" template, and where you can use your own design ... to my knowledge, there is no CMS in existence that won't allow you to use your own custom design. If such a thing actually existed, it would be the worst tool on the planet, and not worth your time. I suppose that list might include those dumb "one-and-one-mywebsite" things that you see advertised on television. But no reputable CMS that I'm aware of at least.