CVE-2026-50386 is a Windows NTFS heap-based buffer overflow that can lead to remote code execution. Microsoft rates it High severity with a CVSS v3.1 base score of 7.8 and temporal score of 6.8. The vector is LOCAL, with LOW attack complexity, NO privileges required, and USER INTERACTION REQUIRED. Microsoft reports no public disclosure and no known exploitation, with exploit code maturity UNPROVEN. Because exploitation requires local access and user interaction, enterprise risk is lower than for remotely reachable, no-interaction flaws, but it can still be significant on systems where untrusted users or code are present.

Highlights:
- CVSS scores: Base 7.8 - Temporal 6.8
- Exploit status & code maturity: Publicly Disclosed: No; Exploited: No; Exploit Code Maturity: UNPROVEN.
- Impact: Remote Code Execution with HIGH confidentiality, integrity, and availability impacts.
- Exploitation likelihood: Exploitation Less Likely; the vector is LOCAL with LOW attack complexity, NO privileges required, and USER INTERACTION REQUIRED.
- Severity for enterprise: High technical severity, but lower enterprise exposure than network-reachable, no-authentication vulnerabilities because exploitation is local and requires user interaction.
- 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