Earlier today, the source code for Counter-Strike: Global Offensive and Team Fortress 2 began to circulate, alarming players and modders who feared to reveal security breaches. At least one project to close as a precaution. However, the game code was previously available, this leak simply spread it much more widely.
We have reviewed the disclosed code and believe it is a redistribution of a limited CS: GO engine code repository released to partners in late 2017 and originally disclosed in 2018. Based on this review, we do not found no reason to alarm players. or avoid the current versions.
– CS: GO (@CSGO) April 22, 2020
According to Valve, in a statement posted on the CS: GO Twitter account, they “believe it is a redistribution of a limited CS: GO engine code repository published to partners in late 2017 and originally disclosed in 2018” and found no reason to be alarmed among players. SteamDB operator Pavel Djundik suggested similar, saying it would likely provide “very little” help to trick developers.