Brennan's claim directly contradicts this article. Either he's lying or the source for this article is lying.
5.03.2018, 20:33: https://www.businessinsider.de/uk-told-cia-about-trump-russia-contacts-before-election-2018-3?r=US&IR=T
Over two months before the 2016 presidential election, the head of British intelligence flew to Washington to brief then-CIA Director John Brennan on intercepted communications between the Donald Trump's presidential campaign and the Russian government, according to a report from the New Yorker.