According to a tweet that was also retweeted by the user @floesen_ who was mentioned in the original thread, the initial report 2 years ago was done using HackerOne but has probably not seen any helpful response from Valve [1].
There are also other reports of Valve not reacting to HackerOne reports appropriately [2].
It is currently unclear whether there is a publicly available PoC or any exploitation going on in the wild.
It is currently unclear whether there is a publicly available PoC or any exploitation going on in the wild.
[1] https://twitter.com/AntiCheatPD/status/1380873722966503426
[2] https://twitter.com/killa/status/1380872852090540032