Valve has no control over user-owned servers, only the listings for the server browser. Valve was informed of this leak years ago. All of this talk of an RCE is

Valve has no control over user-owned servers, only the listings for the server browser. Valve was informed of this leak years ago. All of this talk of an RCE is pure speculation; the leak hasn't even been out for a day. It's good to be informed and take steps toward being safe, but we're talking about a leak where any meaningful security flaws have had multiple years to be patched.