1.4. UEFI Secure Boot and Beta release requirements
If you plan to install a Beta release of Red Hat Enterprise Linux, on systems having UEFI Secure Boot enabled, first disable the UEFI Secure Boot option and then begin the installation.
UEFI Secure Boot requires that the operating system kernel is signed with a recognized private key, which the system’s firmware verifies using the corresponding public key.
For Red Hat Enterprise Linux Beta releases, the kernel is signed with a Red Hat Beta-specific public key, which the system fails to recognize by default. As a result, the system fails to even boot the installation media.