Time-of-check Time-of-use (TOCTOU) Race Condition in Microsoft Windows - CVE-2026-83504
Published: October 14, 2026
Vulnerability identifier: #VU154739
CSH Severity: Low
CVSS v4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-83504
CWE-ID: CWE-367
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to disclose sensitive information.
The vulnerability exists due to a time-of-check time-of-use (TOCTOU) race condition in Windows SmartScreen when handling local operations. A local user can win the race condition to disclose sensitive information.
The exposed information includes heap memory from a privileged process running on the server.
Affected software
Microsoft Windows
How to mitigate CVE-2026-83504
Install security update from vendor's website.
Microsoft Windows - addressed in versions 11 23H2 10.0.22631.7582, 11 24H2 10.0.26100.9445, 11 25H2 10.0.26200.9445, 11 26H1 10.0.28000.2954