CVE-2026-108463: Windows SmartScreen Security Feature Bypass Vulnerability

Overview

Severity

High (CVSS 8.8)

CVSS Vector

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

Category

Security Feature Bypass

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2026-Oct

Released

2026-10-13

Description

Improper resolution of path equivalence in Windows SmartScreen allows an unauthorized attacker to bypass a security feature over a network.

FAQ

How could an attacker exploit this vulnerability? An attacker could convince a user to install an application from a specially crafted link. Successful exploitation could bypass SmartScreen's source reputation checks and allow the application to proceed with installation.

Affected Products (8)

Windows

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

Security Updates (2)

• 5127648
• 5127646

Acknowledgments

yhw

Revision History

• 2026-10-13: Information published.