An update has been released for Left 4 Dead. - Fixed a client crash in weapon sounds. - Fixed a bug that allowed malicious servers to execute restricted console commands on players. - Fixed a bug that allowed malicious servers to prevent players from executing console commands.

An update has been released for Left 4 Dead 2. - Fixed a server lagging exploit. - Fixed some reported security exploits. - Fixed key bindings not displaying correctly when using the Xbox 360 controller. New EMS scripting features: - Added a new interface for reading/writing entity network and data table fields from script. Use "script_help NetProp" for interface details. - New script function "TakeDamage( amount, type, attacker )". - New script function "GetNetworkIDString()". - Added "timeofday" keyfield to the world entity. - Support auto_spawn of witch bride.

An update has been released for Left 4 Dead 2. - Fixed an issue on some MacBook Pro models that prevented the game from rendering correctly, resulting in a blank or white screen with game running in the background. This fix required a change to the minimum spec from MacOS 10.6.4 to MacOS 10.7 (Lion) or higher, which matches Steam's minimum spec.

An update has been released for Left 4 Dead 2. - Fixed multiple potential remote code execution exploits. - Speculative fix for Mac startup rendering issue. - Updated Steam API version.

An update has been released for Left 4 Dead 2. - Fixed two exploits that could allow remote code execution on clients and servers. - Disabled some debug tracking that was causing a crash.

An update has been released for Left 4 Dead. - Fixed exploits that could allow remote code execution. - Remove forced shutdown when ctrl-alt-del is pressed. - Protect against a reported crash caused by a map name parsing failure. - Protect against a reported crash when returning to a lobby.