Examples associated with basic input/output system (BiOS) security are described. One example includes detecting a mismatch between an active BiOS setting and a saved BIOS setting. An update previously applied to the active BiOS setting is validated. The update Is applied to the saved BIOS setting creating an updated BIOS setting. The saved BIOS setting is updated when the updated BIOS setting and the active BIOS setting match. The saved BIOS setting is updated to the active BIOS setting. A security action is taken when the updated BiOS setting and the active BiOS setting differ.