If you have an Asus, Gigabyte, MSI, or ASRock motherboard, you need to update the BIOS if you want to continue playing Valorant. That's because a critical flaw was recently found that allows cheaters to bypass hardware-based security checks and potentially inject code before Riot's Vanguard anti-cheat can wake up.
As laid out in the Riot Games blog (via Tom's Hardware), Valorant relies on IOMMU (Input-Output Memory Management Unit) to check the ID of your memory and only allow greenlit devices to get access.
