Severity by source
AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Local low-privileged access only (AV:L/PR:L), use-after-free race gives AC:H, no UI needed, and kernel compromise yields full C:H/I:H/A:H with no scope change.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
2DescriptionCVE.org
Use after free in Windows NTFS allows an authorized attacker to elevate privileges locally.
AnalysisAI
Local privilege escalation in Microsoft Windows NTFS (New Technology File System) driver lets an already-authenticated low-privileged user corrupt kernel memory via a use-after-free (CWE-416) and elevate to SYSTEM. The flaw affects a broad Windows client and server matrix (Windows 10 1809 through Windows 11 26H1, Windows Server 2019/2022/2025). It has no public exploit identified at time of analysis and is not on CISA KEV, but as a Microsoft-reported, patched NTFS kernel bug it is a routine patch-priority item on standard Patch Tuesday cycles.
Technical ContextAI
NTFS is the default on-disk file system driver (ntfs.sys) that ships in every supported Windows client and server edition, running in kernel mode. The root cause is a use-after-free (CWE-416): the driver continues to reference a heap object after it has been freed, allowing an attacker to reclaim and control that memory to corrupt kernel state. The affected CPE set is exclusively Microsoft operating systems - Windows 10 versions 1809/21H2/22H2, Windows 11 24H2/25H2/26H1, and Windows Server 2019 (incl. Server Core), 2022, and 2025 - indicating the vulnerable code path is in the core OS file-system component rather than any optional feature. Because file-system I/O is reachable from ordinary user-mode processes, a local user can drive the vulnerable code without special roles.
RemediationAI
Apply the Microsoft security update for CVE-2026-50672 (Patch available per vendor advisory) via Windows Update or WSUS/Intune for every affected edition; consult the MSRC guidance at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50672 for the exact KB and build numbers per OS version, as the input does not enumerate a single fix build. No specific vendor workaround is documented for this NTFS driver flaw, and because NTFS is the core file system it cannot be disabled; as compensating controls, prioritize patching internet-exposed and multi-user/terminal servers first, restrict who can run untrusted code locally (application allow-listing, limiting interactive/RDP logon rights), and rely on standard-user least privilege plus EDR to detect local exploitation attempts - these reduce the pool of attackers who can reach the local attack surface but do not close the vulnerability itself.
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Same weakness CWE-416 – Use After Free
View allSame technique Use After Free
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-44128
GHSA-55c6-ggfm-jm78