Insufficient Granularity of Access Control in Microsoft Windows and Windows Server - CVE-2026-83499
Published: October 14, 2026
Vulnerability identifier: #VU154737
CSH Severity: Low
CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-83499
CWE-ID: CWE-1220
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to escalate privileges and execute code in the security context of the NT AUTHORITYNetwork Service account.
The vulnerability exists due to insufficient granularity of access control in Windows Server Update Service when authorizing local access. A local user can exploit the insufficiently granular access controls to escalate privileges and execute code in the security context of the NT AUTHORITYNetwork Service account.
Affected software
Microsoft Windows
Windows Server
Windows Server
How to mitigate CVE-2026-83499
Install security update from vendor's website.
Microsoft Windows - addressed in versions 10 1607 10.0.14393.9612, 10 1809 10.0.17763.9376
Windows Server - addressed in versions 2012 R2 6.3.9600.23470, 2012 6.2.9200.26434, 2016 10.0.14393.9612, 2019 10.0.17763.9376, 2022 10.0.20348.5761, 2025 10.0.26100.33650
Windows Server - addressed in versions 2012 R2 6.3.9600.23470, 2012 6.2.9200.26434, 2016 10.0.14393.9612, 2019 10.0.17763.9376, 2022 10.0.20348.5761, 2025 10.0.26100.33650