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Windows Kernel-Mode Drivers

CVE-2026-20859 — Windows Kernel-Mode Driver Elevation of Privilege Vulnerability

Important CVSS 7.8 EPSS 0.0046 2026-01 archive

Executive Summary

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

Overview

7.8
CVSS HIGH
Important
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
Category Elevation of Privilege
Released Jan 13 2026
Last Updated Jan 13 2026
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.0046 — 0.36296 percentile
NVD CVSS 7.8 HIGH — matches MSRC

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
ATTACK VECTOR
Local
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
Low
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
High
INTEGRITY
High
AVAILABILITY
High
EXPLOIT CODE MATURITY
Unproven
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 6.8

EPSS Score

0.0046
probability of exploitation in the next 30 days
0.36296 percentile - updated 2026-06-21
View on FIRST.org

Affected Products

6 affected products
Product KB Article Severity Impact Restart Required
Windows 11 Version 24H2 for ARM64-based Systems 5074109 (Security Update) Important Elevation of Privilege Yes
Windows 11 Version 24H2 for x64-based Systems 5074109 (Security Update) Important Elevation of Privilege Yes
Windows 11 Version 25H2 for ARM64-based Systems 5074109 (Security Update) Important Elevation of Privilege Yes
Windows 11 Version 25H2 for x64-based Systems 5074109 (Security Update) Important Elevation of Privilege Yes
Windows Server 2025 5073379 (Security Update) Important Elevation of Privilege Yes
Windows Server 2025 (Server Core installation) 5073379 (Security Update) Important Elevation of Privilege Yes

Patches

2 patches
Article Type Restart
5074109 Security Update Yes
5073379 Security Update Yes

Known Exploits

Acknowledgments

hazard

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