What is CVE-2026-77899?

CVE-2026-77899 is a security advisory published by Microsoft Security Response Center (MSRC) with High severity. Windows Security Center Elevation of Privilege Vulnerability

Which CVE IDs does CVE-2026-77899 cover?

CVE-2026-77899 covers the following CVE IDs: CVE-2026-77899. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2026-77899?

CVE-2026-77899 has a CVSS v3 base score of 7.0, published by Microsoft Security Response Center (MSRC).

Which products are affected by CVE-2026-77899?

CVE-2026-77899 affects 8 products, including: Windows 11 Version 24H2 for ARM64-based Systems; Windows 11 Version 24H2 for x64-based Systems; Windows 11 Version 25H2 for ARM64-based Systems; Windows 11 Version 25H2 for x64-based Systems; Windows 11 Version 26H1 for ARM64-based Systems; and others — see the full list on the advisory page.

CVE-2026-77899HighCVSS 7.0

Windows Security Center Elevation of Privilege Vulnerability

Vendor

Microsoft Security Response Center (MSRC)

Published

September 11, 2026

Last Modified

—

🔗 CVE IDs covered (1)

CVE-2026-77899 →

📋 Description

Use after free in Windows Security Center allows an authorized attacker to elevate privileges locally.

🎯 Affected products8

Windows 11 Version 24H2 for ARM64-based Systems
Windows 11 Version 24H2 for x64-based Systems
Windows 11 Version 25H2 for ARM64-based Systems
Windows 11 Version 25H2 for x64-based Systems
Windows 11 Version 26H1 for ARM64-based Systems
Windows 11 version 26H1 for x64-based Systems
Windows Server 2012
Windows Server 2012 (Server Core installation)

✅ Remediation

KB5124008 (Security Update) — fixed build 10.0.26200.9445 KB5124008 (Security Update) — fixed build 10.0.26100.9445 KB5124012 (Security Update) — fixed build 10.0.28000.2954 KB5123065 (Monthly Rollup) — fixed build 6.2.9200.26349

🔗 References (7)

advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-77899
patchhttps://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5124008
referencehttps://support.microsoft.com/help/5124008
patchhttps://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5124012
referencehttps://support.microsoft.com/help/5124012
patchhttps://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5123065
referencehttps://support.microsoft.com/help/5123065