Windows Kernel Elevation of Privilege Vulnerability

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

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7.8CVSS out of 10High severity

Scope

What the vendor says is affected

Windows 11 version 26H1 for x64-based Systems
Windows 11 Version 26H1 for ARM64-based Systems

Versions the vendor lists as fixed

10.0.28000.2525

Next step

What the vendor recommends

Install KB5101649.

Review the complete instructions on the vendor's site

Timeline

When this advisory changed

Jul 14, 2026 at 7:00 AM UTC
Published by Microsoft Security Response Center
The publication date reported by the vendor.
Sep 2, 2026 at 11:20 PM UTC
Added to SecurityAlert
We collected the advisory from the official source.
Sep 3, 2026 at 5:25 AM UTC
Confirmed at the source
Our collector saw this advisory during a later source check.

Vulnerabilities

CVEs named in this advisory

CVE-2026-49173View CVSS, KEV, EPSS, and threat context

Source

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Vendor: Microsoft Security Response Center
Advisory ID: CVE-2026-49173
Last source check: Sep 13, 2026 at 2:40 AM UTC

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Your environment

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What the vendor says is affected

Versions the vendor lists as fixed

What the vendor recommends

When this advisory changed

CVEs named in this advisory

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