An update has been released for Left 4 Dead 2:

- Fixed two exploits that could crash remote servers.
- Fixed missing lobby state messages.
- Fixed community server searches not always returning the full set of lowest-ping results.

An update has been released for Left 4 Dead 2:

- Improved the reliability of "mm_dedicated_force_official_servers" to find the lowest ping server across the supplied IPs.

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 Left 4 Dead:

- Fixed several vulnerabilities and exploits, reported via HackerOne.
- Localization fixes, added Latin American Spanish.

An update has been released for Left 4 Dead 2:

- Fixed several vulnerabilities and exploits reported via HackerOne.

An update has been released for Left 4 Dead 2.

Tank Run mutation fixes based on feedback from Tank Run community groups:
- Removed auto-revive.
- Re-enabled water slowdown.
- Re-enabled crawling when incapped.
- Lowered revive health to 40.
- Revive duration set to 3 seconds.
- Fixed issue where Tanks deleted by triggers were still counted as alive.
- Starting the two extra generators in Sacrifice finale will now decrease the finale timer by 30 seconds and spawn a Tank for each generator.
- Fixed issue where Tanks wouldn't spawn if some players were still connecting.