CVE-2026-57092 - Microsoft Windows VMSwitch Elevation of Privilege Vulnerability is a use-after-free issue in Microsoft Windows VMSwitch. Microsoft says successful exploitation could allow an attacker to gain elevated privileges on the host system beyond the guest virtual machine boundary. The CVSS v3.1 base score is 9.9 (Critical) with a temporal score of 8.6; the vector is NETWORK, LOW attack complexity, LOW privileges required, NO user interaction, and CHANGED scope, with HIGH confidentiality, integrity, and availability impact. Microsoft lists the exploit status as not publicly disclosed and not exploited, with exploit code maturity UNPROVEN. Because the attack is network-reachable and can be initiated from code running in a guest virtual machine, this is a high-severity enterprise risk for Hyper-V environments.

Highlights:
- CVSS scores: Base 9.9 - Temporal 8.6
- Exploit status & code maturity: Publicly Disclosed: No; Exploited: No; Exploit Code Maturity: UNPROVEN.
- Impact: Elevation of Privilege with HIGH confidentiality, HIGH integrity, and HIGH availability impacts.
- Exploitation likelihood: Exploitation Less Likely; network vector with LOW attack complexity, LOW privileges required, and NO user interaction.
- Severity for enterprise: Critical severity. Risk is highest for Hyper-V deployments because exploitation can affect the host from a guest VM, but Microsoft does not report active exploitation.
- 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