CVE-2026-54125 is a Windows Runtime elevation of privilege vulnerability caused by a race condition due to improper synchronization. Microsoft rates it as HIGH severity with a CVSS v3.1 base score of 7.8 and temporal score of 6.8. The attack vector is LOCAL, with LOW attack complexity, LOW privileges required, and no user interaction. If successfully exploited, an attacker could gain SYSTEM privileges. Microsoft reports no public disclosure and no known exploitation; exploit code maturity is UNPROVEN. Because this is local-only and requires existing access on the target system, enterprise risk is lower than for network-exposed issues, but it remains significant on systems where local code execution or low-privilege access is possible.

Highlights:
- CVSS scores: Base 7.8 - Temporal 6.8
- Exploit status & code maturity: Publicly Disclosed: No; Exploited: No; Exploit Code Maturity: UNPROVEN.
- Impact: Elevation of Privilege; confidentiality, integrity, and availability impacts are all HIGH. Successful exploitation can grant SYSTEM privileges.
- Exploitation likelihood: Exploitation Less Likely; the vector is LOCAL with LOW attack complexity, LOW privileges required, and no user interaction.
- Severity for enterprise: High severity per CVSS, but enterprise exposure is reduced by the local attack vector. Risk is most relevant on endpoints or servers where attackers can already run code or obtain low-privilege access.
- Patch status: available; customer action is required.

Affected systems:
- Windows 10 1809
- Windows 10 21H2
- Windows 10 22H2
- Windows 11 24H2
- Windows 11 25H2
- Windows 11 26H1
- Windows 11 unspecified
- Windows Server 2019
- Windows Server 2022
- Windows Server 2025