CVE-2026-50422 is a Windows NTFS 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, attack complexity is LOW, privileges required are LOW, and no user interaction is required. If exploited, an attacker could gain SYSTEM privileges, with HIGH confidentiality, integrity, and availability impact. Microsoft reports no public disclosure and no known exploitation, with exploit code maturity UNPROVEN. Enterprise risk is primarily on systems where a local attacker can already run code or obtain low privileges, rather than on 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 all HIGH. Successful exploitation could grant SYSTEM privileges.
- Exploitation likelihood: Microsoft labels this as Exploitation Less Likely. The vector is LOCAL with LOW attack complexity, LOW privileges required, and NO user interaction.
- Severity for enterprise: High technical severity, but lower exposure for internet-facing infrastructure because the issue is local-only. Higher concern on multi-user Windows systems where untrusted local code or low-privileged users may be present.
- Patch status: available; customer action is 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