U-Boot, short for the Universal Boot Loader, is a first-stage and second-stage bootloader. It is responsible for the initial hardware configuration and loading the operating system (OS) kernel.

GRUB2, U-boot, and Barebox released security updates for the vulnerabilities in February 2025, so updating to the latest versions should mitigate the flaws. 8 Common Threats in 2025.

U-Boot 2025.01-rc1 is currently available as a newer version that fixes these vulnerabilities. The updated sources can be found in the U-Boot project repository.

Microsoft’s Threat Intelligence team has leveraged its AI-driven Security Copilot tool to identify 20 critical vulnerabilities in widely used open-source bootloaders — GRUB2, U-Boot, and Barebox.