EDK II flaw exposes shared firmware to boot-time code execution
Anthropic's Alex Matrosov and Google's Dan Holmes found a 9.5-rated memory-corruption flaw in TianoCore EDK II that can enable code execution before the operating system loads. AMI posted a public pull request with patch code before the planned coordinated disclosure; the flaw is CVE-2026-97631 and also affects Microsoft's Project Mu.
A specially formed Internet Control Message Protocol (ICMP) packet can corrupt memory in firmware's network-handling code before the operating system starts, when protections such as Secure Boot have not yet taken effect. The initial payload runs only once, but can give an attacker an opening to add other early-boot payloads that run on later starts.
For organizations using servers built on EDK II-derived firmware, remediation depends on hardware and cloud providers shipping updates for their models. An operating-system patch cannot reach this layer, so exposure persists until the relevant firmware updates arrive.