CVE-2026-50417 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 attack only (AV:L), with low attack complexity, low privileges required, no user interaction, and unchanged scope. Microsoft reports no public disclosure and no known exploitation, with exploit code maturity marked UNPROVEN. Because the attack is local rather than network-based, enterprise risk is lower for internet-facing services, but it remains relevant for systems where untrusted local code or users may be 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, LOW privileges required, and NO user interaction.
- Severity for enterprise: High technical severity, but lower exposure risk than network-reachable vulnerabilities because exploitation requires local access. Risk is more relevant on shared, multi-user, or untrusted-code environments.
- 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