CVE-2026-56176 is a Windows Win32k elevation of privilege vulnerability caused by an out-of-bounds read. Microsoft rates it 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, no known exploitation, and exploit code maturity is UNPROVEN. Enterprise risk is primarily for systems where untrusted local code or users can run, since this is not a remote/network-exploitable issue.

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 HIGH, integrity HIGH, availability HIGH; successful exploitation could grant SYSTEM privileges
- Exploitation likelihood: Exploitation Less Likely; local vector with LOW attack complexity, LOW privileges required, and no user interaction
- Severity for enterprise: High severity, but risk is mainly on local attack paths rather than internet-facing services
- 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 2012
- Windows Server 2012 R2
- Windows Server 2016
- Windows Server 2019
- Windows Server 2022
- Windows Server 2025