CVE-2025-26634: Windows Core Messaging Elevation of Privileges Vulnerability

Overview

Severity

High (CVSS 7.5)

CVSS Vector

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

Category

Elevation of Privilege

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2025-Mar

Released

2025-03-11

EPSS Score

0.41% (percentile: 61.1%)

Description

Heap-based buffer overflow in Windows Core Messaging allows an authorized attacker to elevate privileges over a network.

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 gather information specific to the environment and take additional actions prior to exploitation to prepare the target environment. What privileges could be gained by an attacker who successfully exploited this vulnerability? An attacker who successfully exploited this vulnerability could gain SYSTEM privileges.

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)

• 5052000
• 5051979
• 5051974
• 5051989
• 5051987
• 5051980
• 5052040
• 5052006

Acknowledgments

YanZiShuang@BigCJTeam of cyberkl

Revision History

• 2025-03-11: Information published. This CVE was addressed by updates that were released in February 2025, but the CVE was inadvertently omitted from the February 2025 Security Updates. This is an informational change only. Customers who have already installed the February 2025 updates do not need to take any further action.