Use-after-free in Microsoft Windows and Windows Server - CVE-2026-77899
Published: September 9, 2026
Vulnerability identifier: #VU148197
CSH Severity: Low
CVSS v4: 7.3 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-77899
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to escalate privileges.
The vulnerability exists due to use-after-free in Windows Security Center when exploiting a race condition. A local user can win a race condition to escalate privileges.
Successful exploitation could grant SYSTEM privileges.
Affected software
Microsoft Windows
Windows Server
Windows Server
How to mitigate CVE-2026-77899
Install security update from vendor's website.
Microsoft Windows - addressed in versions 11 24H2 10.0.26100.9445, 11 25H2 10.0.26200.9445, 11 26H1 10.0.28000.2954
Windows Server - update to 2012 6.2.9200.26349
Windows Server - update to 2012 6.2.9200.26349