Windows LUAFV: Heap-based buffer overflow enables local privilege escalation

Summary

Microsoft has fixed a heap-based buffer overflow in the Windows LUA File Virtualization Filter Driver (LUAFV), tracked as CVE-2026-88230. An attacker who already holds a local account or runs code as a standard user can exploit it to gain higher privileges on the system. Remote exploitation is not possible and no user interaction is required. The risk is highest on multi-user systems such as terminal servers, file servers and shared workstations.

Affected

• Windows 10 Version 1607 and Windows Server 2016 (incl. Server Core): 10.0.14393.0 to before 10.0.14393.9688
• Windows 10 Version 1809 and Windows Server 2019 (incl. Server Core): 10.0.17763.0 to before 10.0.17763.9487
• Windows 10 Version 21H2: 10.0.19044.0 to before 10.0.19044.7846
• Windows 10 Version 22H2: 10.0.19045.0 to before 10.0.19045.7846
• Windows 11 Version 23H2: 10.0.22631.0 to before 10.0.22631.7711
• Windows 11 Version 24H2: 10.0.26100.0 to before 10.0.26100.9974
• Windows 11 Version 25H2: 10.0.26200.0 to before 10.0.26200.9974
• Windows 11 Version 26H1: 10.0.28000.0 to before 10.0.28000.3501
• Windows 11 Version 26H2: 10.0.26300.0 to before 10.0.26300.9974
• Windows Server 2022: 10.0.20348.0 to before 10.0.20348.5870
• Windows Server 2025: affected per the MSRC advisory, exact range unknown.

Fixed in

• Windows 10 1607 and Server 2016: 10.0.14393.9688 (CNA record)
• Windows 10 1809 and Server 2019: 10.0.17763.9487 (CNA record)
• Windows 10 21H2: 10.0.19044.7846 (CNA record)
• Other versions: fix shipped in the November 2026 Patch Tuesday cumulative updates. Unverified third-party builds: 22H2 10.0.19045.7846, 23H2 10.0.22631.7711, 24H2 10.0.26100.9974, 25H2 10.0.26200.9974, 26H1 10.0.28000.3501, Server 2022 10.0.20348.5870. Verify against the MSRC advisory.
• Windows 11 26H2 and Server 2025 (Core): fixed build unknown.

Workaround

Unknown. No vendor-documented workaround was found.

Exploitation

• Microsoft reports Exploited: No at the time of publication.
• Exploitability index: Exploitation More Likely (Tenable roundup).
• Public proof of concept: none found.
• CISA KEV: not found.
• CISA SSVC: Exploitation none, Automatable no, Technical Impact total.
• NVD: awaiting analysis.

Our recommendation

• Install the November 2026 cumulative update on all affected Windows systems, using the KB number listed in the MSRC advisory for each product.
• Prioritise terminal servers, file servers and shared hosts (medium to high); apply single-user workstations in the regular Patch Tuesday cycle.
• Windows 10 1607 and 1809 are out of support; without ESU they will not receive this fix, so upgrade or isolate them.
• Limit local accounts and restrict standard-user code execution where possible.
• Check the MSRC page for updates to exploitation status and mitigations.

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

• Microsoft Security Update Guide (MSRC) msrc.microsoft.com
• CVE Record (CVE Program) www.cve.org
• Tenable: Microsoft November 2026 Patch Tuesday www.tenable.com
• Qualys: Microsoft Patch Tuesday November 2026 review blog.qualys.com
• Strix: CVE-2026-88230 (unverified build data) 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, 03:18.