An update has been released for Left 4 Dead 2. - Configuration files are no longer loaded from addon vpks. These configuration values were sometimes used for malicious purposes, and all changes remained in the user's local settings even after the addon was disabled or removed. When necessary, addon authors should inform users of any required configuration changes in the description on the workshop page.

An update has been released for Left 4 Dead. - Additional fixes to prevent malicious servers from executing restricted console commands on clients.

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.