Langer resigned last week after being offered a mere six-month contract extension despite leading Australia to the T20 World Cup title and a 4-0 Ashes romp.
Past players, including Mark Waugh, Adam Gilchrist, Ricky Ponting, Steve Waugh, and Matthew Hayden, have lambasted Cricket Australia for its handling of the situation.
The silence from the current batch of senior Australian cricket stars has been deafening, which has further inflamed the situation.
Former Test star Mitchell Johnson savaged Cummins last week, saying his former teammate had failed in his first big test as captain.
Johnson was particularly critical of the way Cummins failed to adequately address the situation regarding Langer's future during recent interviews.
Clarke says Cummins is in a "lose-lose" situation, but the star paceman has a responsibility to be truthful about exactly what went down.
"The Australian public aren't stupid and this is my point with Pat Cummins," Clarke told The Big Sports Breakfast.
"Patty needs to come out and make his opinion very clear.
"I saw Mitchell Johnson's comments, he smoked him. I think a lot of people are thinking what Mitch is thinking.
"I'm suggesting to Pat Cummins as the leader, he needs to stand tall and explain to past players — Mitchell Johnson, Steve Waugh, Ricky Ponting, Matthew Hayden — plus the fans and cricket lovers, what the hell is going on here.
"My question is how much involvement did Pat have? Did he want this change and, (if so), why? Bring on accountability.
"When you lose, that's on you as captain. If this is what Patty wants, respect to him but he's going to have to take the hits as well."
Cricket Australia boss Nick Hockley launched a passionate defence of Cummins in the wake of Johnson's comments.
But Clarke said it was imperative for CA to come clean about their reasons for not wanting Langer to stay on long term, or risk repeating the same mistakes from the aftermath of the sandpaper scandal in South Africa.
"We kept so much information away from the public, it's never going to die," Clarke said.
"There's still questions. This will be the same if it's not handled the right way.
"At the moment there is so much unknown, so many Chinese whispers, people hiding behind a journalist or a manager, it doesn't work like that with cricket in this country.
"That's fine if senior players want JL gone. Say it and be honest. It's fine if support staff wanted JL gone.
"Stand there and tell us the reasons. You can't comprehend it at the moment because we don't have all the information."