VAC Live is Valve's upgraded anti-cheat system for Counter-Strike 2, running machine learning analysis during live matches — not after the fact — so it can detect cheating in real time and cancel an affected match immediately. It replaced the earlier VACnet system when CS2 launched in 2023.

Unlike VACnet, which analyzed completed matches and sent suspicious cases to human reviewers, VAC Live identifies and responds to cheating while the match is still in progress, issuing instant bans and voiding the game. Valve's official developer wiki describes it as "a server-sided machine learning approach which tries to detect any irregular gameplay." A reported August 2024 expansion extended detection to hardware-level cheats, including specialized devices used to bypass software-based detection. A September 2025 update was widely reported to have disrupted the CS2 cheating ecosystem significantly. Over 4.5 million accounts have been banned for cheating in Counter-Strike 2 to date.