More details about Brennan's anti-Trump task force
One member was alleged to be Andrea Kendall-Taylor, a Hillary Clinton donor and colleague of "whistleblower" Eric Ciaramella who was later an important figure in the failed plot to impeach Trump.
Brennan allegedly ignored evidence Putin actually favored Clinton. Analysts reported feeling political pressure to back Brennan despite weak underlying intelligence.
Durham is allegedly using a 50 page report produced by the House Intel Committee (before Schiff took over; Schiff promptly buried it) as a roadmap. This should make Brennan nervous despite his lawyer nervously interjecting that Durham promised he wasn't actually a suspect yet.
Worth noting: generally, Durham's team has not leaked. When we see leaks like this mentioning Durham, it's usually from the other side trying to control the narrative or slow-drip damaging revelations.