CVE-2025-49740: 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
2025-Jul
Released
2025-07-08
EPSS Score
0.31% (percentile: 54.4%)

Description

Protection mechanism failure in Windows SmartScreen allows an unauthorized attacker to bypass a security feature over a network.

FAQ

What kind of security feature could be bypassed by successfully exploiting this vulnerability? An attacker who successfully exploited the vulnerability could evade Mark of the Web (MOTW) defenses. How could an attacker exploit this vulnerability? To exploit this security feature bypass vulnerability, an attacker would need to convince a user to launch malicious files using a launcher application that requests that no UI be shown. According to the CVSS metric, user interaction is required (UI:R). What interaction would the user have to do? A user needs to be tricked into running malicious files.

Affected Products (27)

Windows

  • Windows 10 Version 1809 for 32-bit Systems
  • Windows 10 Version 1809 for x64-based Systems
  • Windows Server 2019
  • Windows Server 2019 (Server Core installation)
  • Windows Server 2022
  • Windows Server 2022 (Server Core installation)
  • Windows 10 Version 21H2 for 32-bit Systems
  • Windows 10 Version 21H2 for ARM64-based Systems
  • Windows 10 Version 21H2 for x64-based Systems
  • Windows Server 2025 (Server Core installation)
  • Windows 11 Version 23H2 for ARM64-based Systems
  • Windows 11 Version 23H2 for x64-based Systems
  • Windows Server 2022, 23H2 Edition (Server Core installation)
  • Windows 11 Version 24H2 for ARM64-based Systems
  • Windows 11 Version 24H2 for x64-based Systems
  • Windows Server 2025
  • Windows 10 for 32-bit Systems
  • Windows 10 for x64-based Systems
  • Windows 10 Version 1607 for 32-bit Systems
  • Windows 10 Version 1607 for x64-based Systems
  • Windows Server 2016
  • Windows Server 2016 (Server Core installation)

ESU

  • Windows 11 Version 22H2 for ARM64-based Systems
  • Windows 11 Version 22H2 for x64-based Systems
  • Windows 10 Version 22H2 for x64-based Systems
  • Windows 10 Version 22H2 for ARM64-based Systems
  • Windows 10 Version 22H2 for 32-bit Systems

Security Updates (8)

Acknowledgments

Simon Zuckerbraun of Trend Zero Day Initiative, <a href="https://infosec.exchange/@wdormann">Will Dormann</a> with <a href="https://vu.ls/">Vul Labs</a>

Revision History

  • 2025-07-08: Information published.