Holy Hannah's Montanas! Pics of the scruffy-voiced, fast-talking FIFTEEN-YEAR OLD flashing her bit parts and making her best jail-bait sexy face have popped up on the Internet ... again.

While she's not shaving her head -- yet -- Miley Cyrus might want to slow her tractor-trailer roll on the road to Spearsville.

This isn't the first time naughty photos of the underage, Jesus-loving, Disney star have ended up online. Shots of Miley in her undies made the rounds this past January.

Someone's getting grounded -- we're just sayin'.

A call to Miley's rep was not immediately returned.