An update has been released for Left 4 Dead 2:

- Fixed several matchmaking lobby exploits.
- The cvar "mm_dedicated_force_servers" now only applies to lobbies with the "Best Available Dedicated" server type as originally intended - for all other lobby types the cvar is ignored. Lobby leaders who wish to force official dedicated server selection due to location or network issues should use the new cvar "mm_dedicated_force_official_servers", which only pulls from available official dedicated servers at the requested IPs.

An update has been released for Left 4 Dead 2:

- Fixed an exploit where reliable network fragments could stall out a server indefinitely.
- Re-enabled uploads by default so sprays will work again.

An update has been released for Left 4 Dead 2:

- Fixed a degenerate case where malformed network packets could delay processing the remainder of the stream, severely impacting server performance.

An update has been released for Left 4 Dead 2:

- Fixed possible corruption of the unreliable network stream during high network loads.
- Increased default command limits to prevent spurious disconnects.

An update has been released for Left 4 Dead 2.

- Added protections against malformed network packets.
- Reduced server-side command limits per client.
- Fixed a regression in script handling of regular expressions.
- Fixed several vulnerabilities and exploits reported via HackerOne.

An update has been released for Portal 2.

- Fixed the ping tool not working in co-op.

An update has been released for Portal 2.

- Fixed not being able to play local splitscreen.

An update has been released for Portal 2.

- Fixed several exploits that could crash a coop partner's game. All reported via HackerOne.

An update has been released for Left 4 Dead 2:

- Fixed several vulnerabilities and exploits reported via HackerOne.

- Fixed several remote code execution and crash exploits against co-op partners. All reported via HackerOne.
- Fixed a regression in targeting some entities with the ping tool.