Windows Kernel Elevation of Privilege Vulnerability

Heap-based buffer overflow 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 Server 2019
Windows Server 2019 (Server Core installation)
Windows Server 2022
Windows Server 2022 (Server Core installation)
Windows Server 2025 (Server Core installation)
Windows Server 2022, 23H2 Edition (Server Core installation)
Windows Server 2025
Windows Server 2016
Windows Server 2016 (Server Core installation)
Windows Server 2012
Windows Server 2012 (Server Core installation)
Windows Server 2012 R2
Windows Server 2012 R2 (Server Core installation)

Versions the vendor lists as fixed

10.0.17763.8755
10.0.20348.5139
10.0.20348.5074
10.0.26100.32860
10.0.26100.32772
10.0.25398.2330
10.0.14393.9140
6.2.9200.26079
6.3.9600.23181

Next step

What the vendor recommends

Install KB5087538. Install KB5087545. Install KB5087424. Install KB5087539. Install KB5087423. Install KB5087541. Install KB5087537. Install KB5087470. Install KB5087471.

Review the complete instructions on the vendor's site

Timeline

When this advisory changed

May 12, 2026 at 7:00 AM UTC
Published by Microsoft Security Response Center
The publication date reported by the vendor.
Sep 27, 2026 at 11:11 PM UTC
Added to SecurityAlert
We collected the advisory from the official source.

Vulnerabilities

CVEs named in this advisory

CVE-2026-35420View CVSS, KEV, EPSS, and threat context

Source

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Vendor: Microsoft Security Response Center
Advisory ID: CVE-2026-35420
Last source check: Sep 27, 2026 at 11:11 PM UTC

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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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