Microsoft Windows LUAFV: Heap-based buffer overflow allows local privilege escalation

Summary

The Windows LUA File Virtualization Filter Driver (LUAFV) contains a heap-based buffer overflow (CWE-122), as published by Microsoft as CNA. An attacker with an existing low-privileged local account, for example after phishing or malware execution, can exploit it to elevate privileges. Successful exploitation would give full control of the host, with high impact on confidentiality, integrity and availability. The attack is local only and requires no user interaction, so it is an escalation step rather than a remote entry point.

Affected

• Windows 10 Version 1607 (before 10.0.14393.9688)
• Windows 10 Version 1809 (before 10.0.17763.9487)
• Windows 10 Version 21H2 (before 10.0.19044.7846)
• Windows 10 Version 22H2 (before 10.0.19045.7846)
• Windows 11 Version 23H2 (before 10.0.22631.7711)
• Windows 11 Version 24H2 (before 10.0.26100.9974)
• Windows 11 Version 25H2 (before 10.0.26200.9974)
• Windows 11 Version 26H1 (before 10.0.28000.3501)
• Windows 11 Version 26H2 (before 10.0.26300.9974)
• Windows Server 2016 incl. Server Core (before 10.0.14393.9688)
• Windows Server 2019 incl. Server Core (before 10.0.17763.9487)
• Windows Server 2022 (before 10.0.20348.5870)

The list is taken from the CNA record and is not yet confirmed on MSRC.

Fixed in

• Install the Microsoft security update for November 2026 that contains the fixed builds listed above. Confirm the exact patch on the MSRC advisory.

Workaround

Unknown.

Exploitation

• CISA SSVC: exploitation none, automatable no, technical impact total.
• No reports of exploitation in the wild and no public proof-of-concept code were found at the time of writing.

Our recommendation

• Check the MSRC advisory for CVE-2026-96117 and confirm the affected builds and the fixing update.
• Patch in the regular November 2026 cycle, starting with terminal servers, RDS hosts, shared workstations and file servers.
• Confirm that every Windows 10 device still receives security updates or is enrolled in Extended Security Updates.
• Until patched, restrict local logon rights on multi-user systems.
• Monitor the Microsoft advisory and CISA KEV for changes in exploitation status.

Public exploits iAttack code is publicly available (PoC on GitHub, Metasploit or Exploit-DB).

PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.

Research sources

• CVE.org CNA record www.cve.org
• Microsoft Security Update Guide (requested, not verified) msrc.microsoft.com
• Strix CVE summary (third-party aggregator) www.strix.ai

Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 02:34.