CVE-2026-54121: Microsoft Windows 10 1607

What is CVE-2026-54121?

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

CVSS8.8 NVD 3.1

SeverityHIGH

ExploitationNo exploitation reported

EPSS1% · P54

Triage statusNo Known Exploit

ActionPatch this week

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWECWE-285

NVD published2026-07-14

NVD last modified2026-07-21

Timeline

2026-07-14Published to the U.S. National Vulnerability Database (NVD)
2026-07-21NVD record last updated
2026-08-18First covered in a defend.network daily briefing

Affected product

Microsoft Windows 10 1607

NVD also lists CPE entries for: Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows Server 2012, Microsoft Windows Server 2016, Microsoft Windows Server 2019

Remediation Steps

Apply the vendor security update for Microsoft Windows 10 1607 as a priority.
Restrict network exposure of the affected service to trusted sources until patched.
Review logs and detections for indicators of exploitation.
Confirm fixed versions against the official vendor advisory before deploying.

References

Referenced in our briefings & reports

Vulnerability Priority Report – Week 3 of August 2026 (August 17 – 23)
GitLab, Forminator WordPress, Azure breach: Critical RCEs and 3.6M records stolen (2026-08-18)

Browse all tracked CVEs in the defend.network CVE database →

🤖 This CVE page is generated by defend.network from NVD, CISA KEV, EPSS, and our verified daily briefings. Severity and exploitation data come from official sources; always verify remediation steps against the official vendor advisory before acting in production.