According to gossip website Holy Moly, U2 will top the bill on Friday, Coldplay on Saturday and Beyoncé on Sunday.
"How do we know?" the gossip site said. "Secrets. We thrive on them. In fact we actually lost a couple of our best informants simply bringing this news to you. They're not dead though, we just stopped answering their calls."
Last year, festival organiser Michael Eavis said that hiring Beyoncé would be "the ideal next step" after her husband Jay-Z headed the Pyramid Stage in 2008.
U2 were originally booked to top the main stage last year but were replaced by Gorillaz after Bono suffered a back injury.