Valorant anti-cheat to require BIOS updates for some PCs

• Riot’s Vanguard anti-cheat will block a subset of Valorant players until their motherboard BIOS includes a security patch. • The change targets a UEFI IOMMU bug (CVE-2025-11901, CVE-2025-14302–14304) that can allow pre-boot DMA access. • Patches are available for many newer Intel and AMD chipsets from ASRock, Asus, Gigabyte and MSI; older boards may not receive fixes. • Riot may expand the BIOS check to top-ranked Valorant tiers and could enable similar restrictions for League of Legends.

What Riot is changing — and why

Riot Games is rolling a BIOS-update requirement into Vanguard, its kernel-level anti-cheat, after researchers disclosed a UEFI bug that undermines pre-boot DMA protections. The flaw can let devices access system RAM during boot even when protections appear enabled, creating an avenue for sophisticated cheats to compromise memory integrity.

Vanguard will initially apply the BIOS check only to a limited group of “restricted” Valorant players whose machines resemble setups used by cheaters. Riot says it may broaden enforcement to high-competitive ranks (Ascendant, Immortal, Radiant) where the incentive to bypass anti-cheat is greatest, and an anti-cheat analyst suggested similar restrictions could be toggled for League of Legends in the future.

Which motherboards and chipsets are affected

Multiple vendors identified impacted boards and released firmware updates for many recent models. ASRock, Asus, Gigabyte, and MSI have posted security bulletins covering various Intel and AMD chipsets; collectively those notices reference Intel 400–800 series and AMD 600–800 series families in different combinations.

That broadly maps to Intel 10th-gen Core and newer, and AMD Ryzen 7000-series and newer platforms. However, several older platforms—AM4-based AMD boards and Intel 300-series motherboards that support 8th/9th-gen CPUs—are not clearly listed for patches, leaving uncertainty for owners of older but otherwise capable PCs.

The technical root: IOMMU and UEFI

The vulnerability impacts the I/O Memory Management Unit (IOMMU) implementation on some UEFI firmware. IOMMU is supposed to block devices from performing direct memory access (DMA) during boot; the bug created a short window where DMA could bypass those controls.

The fixes are tracked as CVE-2025-11901, CVE-2025-14302, CVE-2025-14303, and CVE-2025-14304. Motherboard vendors have published advisories and firmware updates on their support sites.

What players should do now

If Vanguard blocks you from launching Valorant, check your motherboard maker (ASRock, Asus, Gigabyte, MSI or your OEM) for a BIOS/UEFI update and apply the patch following the vendor’s instructions. Back up important data before flashing firmware.

If your board has no update available, contact the OEM to ask about a firmware timeline. Expect this to mainly affect competitive players first, but keep an eye on Riot’s support pages—requirements could widen to more tiers over time.

Bottom line

The change is a targeted security step to close a niche but potent exploit path. It protects game integrity but may force owners of older or unpatched motherboards to pursue firmware or hardware upgrades.