CNN host Jake Tapper on Thursday slammed journalist Glenn Greenwald for attacking him for co-authoring an upcoming book detailing a White House “cover-up” of former President Joe Biden’s reported health decline.

Greenwald — on Tuesday’s episode of his Rumble show “System Update” — claimed Tapper was a key member of the media who helped conceal Biden’s deteriorating condition from the public, adding that he was “demanding and insisting ... that nobody talk about Biden’s cognitive decline.”

A representative for Tapper, in a statement to The Daily Beast on Thursday, scorched Greenwald for doing an “entire segment based on false attacks that could’ve been fact-checked in seconds.”

“Lies from bad faith actors will keep coming for whatever reason but the truths of the book remain,” said the representative.

Tapper — who co-wrote “Original Sin” with Axios’ Alex Thompson, known for covering the circumstances that led to and followed Biden’s train wreck debate performance — has faced further criticism from Fox News over the book. The two authors hired a crisis PR expert to navigate its release, per The Daily Beast.

Greenwald argued that polls reflected how Americans “overwhelmingly” believed Biden was in cognitive decline, was “too old” to run again and wasn’t fit for the Oval Office — claiming that the media were the only ones who pretended this wasn’t the case.

Greenwald, elsewhere on his show, analyzed a supercut of Tapper weighing in on a Wall Street Journal article published weeks prior to Biden’s June 2024 debate against Donald Trump. The newspaper reported at the time that Biden showed “signs of slipping” behind “closed doors.”

Greenwald — whose supercut shows Tapper noting that the WSJ is “owned by News Corp. which is run by the Murdochs” — accused the CNN host of trying to “disparage” the reporting and acting as if it was a “partisan hit-job.”

But, as The Daily Beast noted, Tapper was referring to a then-White House spokesperson’s possibly insinuating that the WSJ was “taking orders” from the Murdochs.

Tapper, in separate remarks during a CNN appearance on Wednesday, noted that he believed “some of the criticism” toward him is “fair to be honest.”

“Knowing then what I know now, I look back at my coverage during the Biden years — and I did cover some of these issues, but not enough — I look back on it with humility,” he said.