gEfiCertDbGuid

GUID used to "certdb"/"certdbv" variable to store the signer's certificates for common variables with EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS attribute.
Include/Guid/AuthenticatedVariableFormat.h

GUID Information

GUID's Guid Name	GUID's Guid
gEfiCertDbGuid	{ 0xd9bee56e, 0x75dc, 0x49d9, { 0xb4, 0xd7, 0xb5, 0x34, 0x21, 0xf, 0x63, 0x7a } }

Refer to Header File

SecurityPkg/Include/Guid/AuthenticatedVariableFormat.h