A brief news report or statement that's written or spoken is a bulletin. A TV reporter might read a bulletin announcing the winner of a presidential election, for example.
You're most likely to hear a bulletin on the radio or television, usually in the form of a news update. A bulletin can also be a written or emailed report or newsletter that gives you brief information. A bulletin board is a message board that has such bulletins pinned to it. The root of bulletin is the Italian bulletta, "document" or "voting slip."