CVE-2026-58632 is a Windows Win32 Kernel Subsystem use-after-free vulnerability that can be exploited for elevation of privilege. Microsoft rates it with a CVSS v3.1 base score of 7.8 and temporal score of 6.8. The attack vector is LOCAL, attack complexity is LOW, privileges required are LOW, and no user interaction is needed. If successfully exploited, a domain user could elevate to SYSTEM assigned integrity level. Microsoft reports no public disclosure and no known exploitation, with exploit code maturity UNPROVEN. Because this is a local privilege escalation issue, it is more relevant to systems where untrusted local users or code are present than to network-exposed 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; confidentiality, integrity, and availability impacts are HIGH
- Exploitation likelihood: Exploitation Less Likely; LOCAL vector, LOW attack complexity, LOW privileges required, and NO user interaction
- Severity for enterprise: High technical severity, but lower risk for internet-facing services because exploitation requires local access and existing low privileges
- Patch status: available; customer action required

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 2016
- Windows Server 2019
- Windows Server 2022
- Windows Server 2025