Review reviewHigh

CVE-2026-54121

Microsoft Windows 10 Version 1607, Windows 10 Version 1809, Windows Server 2012

Improper authorization in Active Directory Certificate Services (AD CS) allows an authorized attacker to elevate privileges over a network.

PRIORITY ASSESSMENT

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability1.05%

Technical severityCVSS 8.8

Improper authorization in Active Directory Certificate Services (AD CS) allows an authorized attacker to elevate privileges over a network.

Product: Microsoft Windows 10 Version 1607, Windows 10 Version 1809, Windows Server 2012
Affected versions: >= 10.0.14393.0 < 10.0.14393.9339, >= 10.0.17763.0 < 10.0.17763.9020, >= 6.2.9200.0 < 6.2.9200.26226, >= 6.3.9600.0 < 6.3.9600.23291, >= 10.0.20348.0 < 10.0.20348.5386, >= 10.0.26100.0 < 10.0.26100.33158, < 10.0.14393.9339, < 10.0.17763.9020, r2, < 10.0.20348.5386, < 10.0.26100.33158
Fixed versions: 10.0.14393.9339, 10.0.17763.9020, 10.0.20348.5386, 10.0.26100.33158

Confirm exposure before applying a vendor-supported change.

1
Identify
Confirm that Microsoft Windows 10 Version 1607, Windows 10 Version 1809, Windows Server 2012 and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.