Insyde InsydeH2O (unverified firmware volume in the boot chain): Certain firmware volumes are executed without being

Impact

Certain firmware volumes are executed without being verified, so the verified-boot chain has a hole in it: an attacker who can write to the unverified FV gets arbitrary code execution in firmware and the platform's own boot integrity check does not object. This is the root-of-trust failure rather than a memory-safety bug - the whole value of measured and verified boot on a GPU node is that unauthorised firmware cannot run, and here it can.

Who can reach it

An attacker able to modify the affected firmware volume - via SPI write access, a malicious capsule, or an earlier compromise with firmware-write privilege. Then any boot.

What to do

OEM BIOS update. Insyde ships fixes per Intel platform: Arrow Lake H/U 05.56.17.0022, Arrow Lake S/HX 05.56.17.0037, Raptor Lake 05.47.24.0058 (mobile) and 05.47.24.0057 (server/embedded), Alder Lake 05.47.24.2057, Meteor Lake 05.56.07.0022, Elkhart Lake 05.48.17.0030 - so check your exact silicon generation, since several platforms are listed unaffected. Advisory dated 2026-08-12, meaning OEM images are only just starting to appear; expect the Dell/HPE/Lenovo/Supermicro rebase to trail by months. Firmware flash, reboot per node. No config workaround. Meanwhile, verify SPI flash write protection is actually enforced (BIOS Lock Enable, protected range registers) so the unverified FV is not writable in the first place.

References