Intel Active Management Technology, Intel Standard Manageability, and Intel Small Business Technology firmware versions 11.0.25.3001 and 11.0.26.3000 anti-rollback will not prevent upgrading to firmware version 11.6.x.1xxx which is vulnerable to CVE-2017-5689 and can be performed by a local user with administrative privileges.
https://security-center.intel.com/advisory.aspx?intelid=INTEL-SA-00082&languageid=en-fr