Researchers have disclosed a critical UEFI firmware vulnerability affecting various motherboards from ASUS, Gigabyte, MSI, and ASRock that allows direct memory access (DMA) attacks to bypass early-boot memory protections, potentially enabling malicious code to compromise systems before the operating system loads. Tracked under multiple CVEs (CVE-2025-11901, CVE-2025-14302, CVE-2025-14303, and CVE-2025-14304) due to vendor implementation differences, the flaw stems from UEFI firmware incorrectly reporting that DMA protections are enabled even when the IOMMU (a hardware memory firewall designed to restrict device access to RAM) fails to initialize during early boot. Discovered by Riot Games researchers Nick Peterson and Mohamed Al-Sharifi and coordinated with CERT Taiwan, the issue allows a malicious PCIe device with physical access to read or modify system memory before OS-level safeguards activate, leaving no alerts, prompts, or logs for detection. While Riot Games highlighted the risk in the context of kernel-level game cheats (causing its Vanguard anti-cheat to block Valorant from launching on vulnerable systems) the underlying exposure extends to broader security threats capable of fully compromising the operating system. Carnegie Mellon’s CERT/CC confirmed broad impact across multiple vendors and warned that exploitation occurs in the system’s most privileged state, underscoring the importance of applying the vendor firmware updates promptly after backing up data.