CVE-2026-23674: MapUrlToZone Security Feature Bypass Vulnerability

Overview

Severity
High (CVSS 7.5)
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
Category
Security Feature Bypass
Exploit Status
Not Exploited
Exploitation Likelihood
Unlikely
Patch Tuesday
2026-Mar
Released
2026-03-10
EPSS Score
0.09% (percentile: 25.5%)

Description

Improper resolution of path equivalence in Windows MapUrlToZone 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 bypass the MapURLToZone method. The Security Updates table indicates that this vulnerability affects all supported versions of Microsoft Windows. Why are IE Cumulative updates listed for Windows Server 2012, and Windows Server 2012 R2? While Microsoft has announced retirement of the Internet Explorer 11 application on certain platforms and the Microsoft Edge Legacy application is deprecated, the underlying MSHTML, EdgeHTML, and scripting platforms are still supported. The MSHTML platform is used by Internet Explorer mode in Microsoft Edge as well as other applications through WebBrowser control. The EdgeHTML platform is used by WebView and some UWP applications. The scripting platforms are used by MSHTML and EdgeHTML but can also be used by other legacy applications. Updates to address vulnerabilities in the MSHTML platform and scripting engine are included in the IE Cumulative Updates; EdgeHTML and Chakra changes are not applicable to those platforms. To stay fully protected, we recommend that customers who install Security Only updates install the IE Cumulative updates for this vulnerability.

Affected Products (31)

Windows

  • Windows 11 Version 26H1 for ARM64-based Systems
  • Windows 11 version 26H1 for x64-based Systems
  • Windows Server 2019 (Server Core installation)
  • Windows Server 2022
  • Windows 10 Version 1809 for x64-based Systems
  • Windows Server 2019
  • Windows 10 Version 1809 for 32-bit Systems
  • Windows Server 2022 (Server Core installation)
  • Windows 10 Version 21H2 for 32-bit Systems
  • Windows 10 Version 21H2 for x64-based Systems
  • Windows 10 Version 21H2 for ARM64-based Systems
  • Windows 11 Version 25H2 for ARM64-based Systems
  • Windows 11 Version 25H2 for x64-based Systems
  • Windows Server 2025 (Server Core installation)
  • Windows 11 Version 23H2 for x64-based Systems
  • Windows 11 Version 23H2 for ARM64-based Systems
  • Windows 11 Version 24H2 for ARM64-based Systems
  • Windows Server 2022, 23H2 Edition (Server Core installation)
  • Windows Server 2025
  • Windows 11 Version 24H2 for x64-based Systems
  • Windows 10 Version 1607 for 32-bit Systems
  • Windows Server 2016 (Server Core installation)
  • Windows Server 2016
  • Windows 10 Version 1607 for x64-based Systems

ESU

  • Windows 10 Version 22H2 for x64-based Systems
  • Windows 10 Version 22H2 for 32-bit Systems
  • Windows 10 Version 22H2 for ARM64-based Systems
  • Windows Server 2012
  • Windows Server 2012 (Server Core installation)
  • Windows Server 2012 R2
  • Windows Server 2012 R2 (Server Core installation)

Security Updates (13)

Acknowledgments

<a href="https://infosec.exchange/@seibai">Jonathan Birch</a> with <a href="https://www.microsoft.com/">Microsoft</a>

Revision History

  • 2026-03-10: Information published.