The nature of dark matter remains one of the biggest open questions in particle physics. Among the intriguing models beyond the Standard Model (SM) that provide explanation to dark matter, hidden valley models propose a dark sector that extends the SM with a non-Abelian gauge group, similar to quantum chromodynamics. A rich phenomenology might result from portal interactions, which connect the dark sector with the SM. In this talk, I will present the most recent results from CMS that explore the dark sector by exploiting dedicated data streams as well as different detector signatures. The most stringent limits to date are imposed on several benchmark models, covering a wide range of parameter space.