Worked on enhancing firmware security and reliability in the microsoft/mu_basecore repository by addressing a critical vulnerability in the System Management Mode (SMM) path. Focused on low-level programming and system programming, the work involved implementing safe handling of the Interrupt Descriptor Table (IDT) register on SMM entry and delaying the enabling of Machine Check Events until after the SMM IDT was reloaded. This mitigation, delivered as a cherry-picked patch, resolved CVE-2025-3770 and included targeted assembly changes for secure register manipulation. The update improved the security posture of the SMM entry path without introducing behavioral regressions in production environments.