Nope, CBD products are not legal in all states. While CBD is still considered illegal under federal law, as it is derived from the cannabis plant (which is classified as a Schedule 1 drug), its medicinal use is legal in 44 U.S. states.
In the 28 states that have legalized medical marijuana, CBD falls under that category. Additionally, 16 states have legalized CBD-only products. However, in states that have opted to allow CBD medicine, but not THC, products can still be difficult to obtain, as there is no market or infrastructure in which to sell them.