The accident, which also involved a motorbike, happened near Bell Common tunnel, between J26 for Waltham Abbey and J27 for the M11 at 15:15 BST.
The carriageway was closed between J25 and J27 but has since reopened.
The injured driver was airlifted to hospital. At 21:58 BST the Highways Agency reported there were still long delays in the area.
The driver of a lorry has been taken to hospital with life-threatening injuries after a crash on the M25 in Essex.