Review reviewHigh

CVE-2026-20859

Microsoft Windows 11 Version 24H2, Windows 11 Version 25H2, Windows Server 2025

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

PRIORITY ASSESSMENT

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability-

Technical severityCVSS 7.8

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

Product: Microsoft Windows 11 Version 24H2, Windows 11 Version 25H2, Windows Server 2025
Affected versions: >= 10.0.26100.0 < 10.0.26100.7623, >= 10.0.26200.0 < 10.0.26200.7623, >= 10.0.26100.0 < 10.0.26100.32230, < 10.0.26100.7623, < 10.0.26200.7623, < 10.0.26100.32230
Fixed versions: 10.0.26100.7623, 10.0.26200.7623, 10.0.26100.32230

Confirm exposure before applying a vendor-supported change.

1
Identify
Confirm that Microsoft Windows 11 Version 24H2, Windows 11 Version 25H2, Windows Server 2025 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.