CVE-2026-58527 is a Windows Runtime Elevation of Privilege vulnerability caused by a race condition in shared resource synchronization. It is rated 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 exploited, it can impact confidentiality, integrity, and availability at high levels. Microsoft reports no public disclosure and no known exploitation, and exploit code maturity is unproven. Because this is a local elevation-of-privilege issue, enterprise risk is higher on systems where untrusted local users or code can run, rather than on network-facing services.

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 with HIGH confidentiality, integrity, and availability impacts.
- Exploitation likelihood: Microsoft indicates Exploitation Less Likely; vector context is LOCAL with LOW attack complexity, LOW privileges required, and NO user interaction.
- Severity for enterprise: High technical severity, but lower exposure than network-based issues because exploitation is local-only. Risk is most relevant on endpoints and servers where local code execution or shared access is possible.
- Patch status: available; customer action required.

Affected systems:
- Windows 11 24H2
- Windows 11 25H2
- Windows 11 26H1
- Windows 11 unspecified
- Windows Server 2022
- Windows Server 2025