CVE-2026-83504: Windows SmartScreen Information Disclosure Vulnerability

Overview

Severity

Medium (CVSS 4.7)

CVSS Vector

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C

Category

Information Disclosure

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2026-Oct

Released

2026-10-13

Description

Time-of-check time-of-use (toctou) race condition in Windows SmartScreen allows an authorized attacker to disclose information locally.

FAQ

According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability? Successful exploitation of this vulnerability requires an attacker to win a race condition. What type of information could be disclosed by this vulnerability? An attacker who successfully exploited this vulnerability could view heap memory from a privileged process running on the server.

Affected Products (8)

Windows

• Windows 11 Version 25H2 for ARM64-based Systems
• Windows 11 Version 25H2 for x64-based Systems
• Windows 11 Version 23H2 for ARM64-based Systems
• Windows 11 Version 23H2 for x64-based Systems
• Windows 11 Version 24H2 for ARM64-based Systems
• Windows 11 Version 24H2 for x64-based Systems
• Windows 11 version 26H1 for x64-based Systems
• Windows 11 Version 26H1 for ARM64-based Systems

Security Updates (3)

• 5124008
• 5122880
• 5124012

Acknowledgments

Microsoft Offensive Research & Security Engineering

Revision History

• 2026-10-13: Information published.