CVE-2026-45595: Windows Mark of the Web Security Feature Bypass Vulnerability

Overview

Severity
Medium (CVSS 5.4)
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L/E:U/RL:O/RC:C
Category
Security Feature Bypass
Exploit Status
Not Exploited
Exploitation Likelihood
Less Likely
Patch Tuesday
2026-Jun
Released
2026-06-09

Description

Protection mechanism failure in Windows Mark of the Web (MOTW) allows an unauthorized attacker to bypass a security feature over a network.

FAQ

According to the CVSS metrics, successful exploitation of this vulnerability could lead to some loss of integrity (I:L) and some loss of availability (A:L). What does that mean for this vulnerability? An attacker can craft a malicious file that would evade Mark of the Web (MOTW) defenses, resulting in a limited loss of integrity and availability of security features such as Protected View in Microsoft Office, which rely on MOTW tagging. How could an attacker exploit the vulnerability? To exploit this vulnerability, an attacker could host a file on an attacker-controlled server, then convince a targeted user to download and open the file. This could allow the attacker to interfere with the Mark of the Web functionality. Please see Additional information about Mark of the Web for further clarification

Affected Products (28)

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 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 Server 2025
  • Windows 11 version 26H1 for x64-based Systems
  • Windows 11 Version 26H1 for ARM64-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 10 Version 22H2 for x64-based Systems
  • Windows 10 Version 22H2 for ARM64-based Systems
  • Windows 10 Version 22H2 for 32-bit Systems
  • Windows Server 2012 R2
  • Windows Server 2012 R2 (Server Core installation)

Security Updates (9)

Acknowledgments

<a href="https://www.linkedin.com/in/rflohil/">Rutger Flohil</a> with https://pampuna.nl/, <a href="https://www.linkedin.com/in/bobvanderstaak/">Bob van der Staak</a> with <a href="https://gripopsecurity.nl/">Grip op Security</a>

Revision History

  • 2026-06-09: Information published.