I have a company that sell posters and recently a company contacted me is concerns about the use of one of their fonts. They asked if I had a commercial license. At first I was confused as I had no idea as the design of the poster was done by a freelancer that I hired. I told them that and I have contacted the freelance but he has yet to respond.

Is it possible that the creator of the font could sue me if he (the freelancer) does not reply or does not have a commercial license?

Well, technically it's not impossible, even if the freelancer should be to blame. If you need an accurate answer, you should really contact a lawyer though.

To avoid a lot of hassle contact the company again and tell them (again) that you were not aware of this and suggest you buy the license after all. My guess is they will accept.