https://www.bleepingcomputer.com/news/security/second-steam-zero-day-impacts-over-96-million-windows-users/

A second Steam Windows client zero-day privilege escalation vulnerability affecting over 96 million users has been publicly disclosed today by Russian researcher Vasily Kravets.

This happens after Valve disputed the significance of the previous Steam 0day disclosed by Kravets on Twitter and banned him out of their HackerOne bug bounty program.