CVE-2026-54107 is a Windows Win32k elevation of privilege vulnerability caused by a race condition (concurrent execution using a shared resource with improper synchronization). It affects multiple Windows client and server versions. Microsoft rates it at CVSS v3.1 8.8 (High) with a local attack vector, low attack complexity, low privileges required, no user interaction, and changed scope. The issue is not publicly disclosed as exploited and exploit code maturity is unproven. Because it requires local access and some privileges, enterprise risk is higher for systems that allow untrusted local code or users, but it is not a network-exposed remote attack.

Highlights:
- CVSS scores: Base 8.8 - Temporal 7.7
- Exploit status & code maturity: Publicly Disclosed: No; Exploited: No; Exploit Code Maturity: UNPROVEN
- Impact: Elevation of Privilege with HIGH confidentiality, integrity, and availability impacts
- Exploitation likelihood: Exploitation Less Likely; local vector, LOW attack complexity, LOW privileges required, and NO user interaction
- Severity for enterprise: High due to CVSS 8.8 and the potential for privilege escalation, but risk is constrained by the LOCAL attack vector rather than network exposure
- Patch status: available

Affected systems:
- Windows 10 1607
- Windows 10 1809
- Windows 10 21H2
- Windows 10 22H2
- Windows 11 24H2
- Windows 11 25H2
- Windows 11 26H1
- Windows 11 unspecified
- Windows Server 2012
- Windows Server 2012 R2
- Windows Server 2016
- Windows Server 2019
- Windows Server 2022
- Windows Server 2025