CVE-2026-20853: Windows WalletService Elevation of Privilege Vulnerability

Overview

Severity: High (CVSS 7.4)
CVSS Vector: CVSS:3.1/AV:L/AC:H/PR:N/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: 2026-Jan
Released: 2026-01-13
EPSS Score: 0.02% (percentile: 6.7%)

Description

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows WalletService allows an unauthorized attacker to elevate privileges locally.

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 win a race condition. What privileges could be gained by an attacker who successfully exploited the vulnerability? An attacker who successfully exploited this vulnerability could gain the privileges of the compromised user.

Affected Products (16)

Windows

Windows 10 Version 1809 for 32-bit Systems
Windows 10 Version 1809 for x64-based Systems
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 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 10 Version 1607 for 32-bit Systems
Windows 10 Version 1607 for x64-based Systems

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

Security Updates (5)

Acknowledgments

<a href="https://twitter.com/hillstone_lab">Zhang WangJunJie, He YiSheng</a> with <a href="https://www.hillstonenet.com/">Hillstone Networks Security Research Institute</a>

Revision History

2026-01-13: Information published.