CVE-2019-1126: Microsoft Windows Server 2012

Medium severity, CVSS 5.3. EPSS: 4.9% chance of exploitation in the next 30 days.

A security feature bypass vulnerability exists in Active Directory Federation Services (ADFS) which could allow an attacker to bypass the extranet lockout policy.To exploit this vulnerability, an attacker could run a specially crafted application, which would allow an attacker to launch a password brute-force attack or cause account lockouts in Active Directory.This security update corrects how ADFS handles external authentication requests., aka 'ADFS Security Feature Bypass Vulnerability'. This CVE ID is unique from CVE-2019-0975.

Affected products

• Microsoft Windows Server 2012: version r2 only
• Microsoft Windows Server 2016: affected versions not specified; version 1803 only; version 1903 only
• Microsoft Windows Server 2019: affected versions not specified

Published 2019-07-15. Last modified 2026-06-17.