CVE-2026-50441 - Windows Resilient File System (ReFS) Elevation of Privilege Vulnerability - is an untrusted pointer dereference issue in ReFS that can lead to elevation of privilege. It has a CVSS v3.1 base score of 7.8 and temporal score of 6.8, with a LOCAL attack vector, LOW attack complexity, LOW privileges required, and no user interaction. Microsoft reports no public disclosure and no known exploitation, with exploit code maturity UNPROVEN. Because the issue is local-only, enterprise risk is primarily to systems where an attacker can obtain local access or execute code with low privileges.

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.
- Exploitation likelihood: Exploitation Less Likely; vector is LOCAL with LOW attack complexity, LOW privileges required, and NO user interaction.
- Severity for enterprise: High technical severity, but lower exposure than network-reachable issues because exploitation requires local access. This is most relevant on multi-user or internally accessible Windows systems.
- 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