A security feature bypass vulnerability exists when Active Directory Federation Services (ADFS) improperly updates its list of banned IP addresses. To exploit this vulnerability, an attacker would have to convince a victim ADFS administrator to update the list of banned IP addresses. This security update corrects how ADFS updates its list of banned IP addresses., aka 'ADFS Security Feature Bypass Vulnerability'. This CVE ID is unique from CVE-2019-1126.