HBO is working on the first authorized biography of Kurt Cobain, titled Kurt Cobain: Montage of Heck. It is set to air exclusively in the U.S. in 2015, and then roll out in theaters internationally. Frances Bean Cobain is executive producing the movie, which will include never-before-seen home movies and previously unheard Cobain originals. The director, Brett Morgen, was "granted unprecedented access to Cobain's archives." Oscar-nominated Morgen also directed the Rolling Stones documentary, Crossfire Hurricane.
Here's another article, 10 Things You Never Knew About Kurt Cobain