CVE-2018-8340: Microsoft Windows Server 2012

Medium severity, CVSS 6.5. EPSS: 7.6% chance of exploitation in the next 30 days.

A security feature bypass vulnerability exists when Active Directory Federation Services (AD FS) improperly handles multi-factor authentication requests, aka "AD FS Security Feature Bypass Vulnerability." This affects Windows Server 2016, Windows Server 2012 R2, Windows 10 Servers.

Affected products

• Microsoft Windows Server 2012: version r2 only
• Microsoft Windows Server 2016: affected versions not specified; version 1709 only; version 1803 only

Published 2018-08-15. Last modified 2026-06-17.