Steam News announces a new automatic update is now available for Left 4 Dead 2, re-adding Last Man on Earth as an encore mutation. The new version also addresses a bug in the co-op shooter, while also closing off a bunch of exploits, saying this is the first in a series of exploit fixes, and that these changes would be coming soon to the Xbox 360 edition of the game. The full patch notes follow.

Left 4 Dead 2

• Encore mutation: Last Man On Earth
• Fixed some missing particle declarations for the Cold Stream campaign

The following map fixes are the first of a series of exploit fixes coming. These will appear on the Xbox 360 in a future update.

Dark Carnival: The Fairgrounds

• Survivors can longer get onto the elevated track.
• Infected players can no longer block the carousel gate.

Dark Carnival: The Coaster

• Survivors can no longer skip the roller coaster crescendo event
• Survivor can no longer use shortcuts on the roller coaster

The Parish: The Park

• Survivors can no longer skip the bus station crescendo event

The Parish: The Cemetery

• Survivors can no longer skip interiors by jumping over a fence or getting onto rooftops