CVE-2026-81963: Windows Update Stack Elevation of Privilege Vulnerability
Improper link resolution before file access ('link following') in Windows Update Stack allows an authorized attacker to elevate privileges locally.
Other sources
Windows Update Stack Elevation of Privilege Vulnerability
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26100.33438Patch KB5122871 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26100.9445Patch KB5124008 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.22631.7582Patch KB5122880 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.28000.2954Patch KB5124012 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26200.9445Patch KB5124008
Event History
Frequently Asked Questions
Who is exposed to this vulnerability?
Systems running Microsoft Windows 11 or Microsoft Windows Server 2025 are identified as affected. Exploitation requires local access by an authorized attacker rather than remote network access.
What level of access does an attacker need?
The attacker needs existing local authorized access with low privileges. No user interaction is required, and successful exploitation can elevate privileges and affect confidentiality, integrity, and availability.
Is exploitation occurring in the wild?
Yes. The vulnerability is flagged as exploited and was added to the Known Exploited Vulnerabilities catalog on 2026-09-08.