Microsoft Windows Kernel: Elevation of privilege via heap-based buffer overflow

Summary

A heap-based buffer overflow in the Windows Kernel allows an authorized local attacker to elevate privileges on affected Windows 10, Windows 11 and Windows Server systems. An attacker needs local code execution or a valid low-privilege account, so the flaw typically serves as a second step after phishing, a stolen credential or malware. Microsoft has published security updates; no exploitation or public exploit code is known.

Affected

• Windows 10 Version 1607 (LTSB 2016): 10.0.14393.0 to < 10.0.14393.9612
• Windows Server 2016 (incl. Server Core): 10.0.14393.0 to < 10.0.14393.9612
• Windows 10 Version 1809: 10.0.17763.0 to < 10.0.17763.9376
• Windows 10 Version 21H2 and 22H2: 10.0.19044.0 to < 10.0.19044.7807 and 10.0.19045.0 to < 10.0.19045.7807
• Windows 11 Version 23H2, 24H2, 25H2, 26H2: see the MSRC advisory for the exact builds
• Windows Server 2012 and 2012 R2 (incl. Server Core): 6.2.9200.0 to < 6.2.9200.26434 and 6.3.9600.0 to < 6.3.9600.23470

Fixed in

• Fixed builds according to the CVE record: 10.0.14393.9612 (1607 and Server 2016), 10.0.17763.9376 (1809), 10.0.19044.7807 (21H2), 10.0.19045.7807 (22H2), 10.0.22631.7652 (23H2), 10.0.26100.9711 (24H2), 10.0.26200.9711 (25H2), 10.0.26300.9711 (26H2), 6.2.9200.26434 (Server 2012), 6.3.9600.23470 (Server 2012 R2)
• KB numbers: check the MSRC advisory for your exact edition
• Windows 10 1607 LTSB: whether Extended Security Updates cover this CVE is unverified

Workaround

• Unknown.
• Limit local user privileges to reduce the risk of code execution with elevated rights (general hardening, not a Microsoft-documented mitigation)

Exploitation

• CISA SSVC: Exploitation none, Automatable no, Technical Impact total
• Not listed in CISA KEV
• Microsoft exploit code maturity: Unproven (E:U)
• No public proof-of-concept or exploit found in the sources; EPSS 0.00318

Our recommendation

• Inventory all Windows 10 1607 / LTSB 2016 and Windows Server 2016 hosts (build 14393)
• Decide now on migration or ESU for Windows 10 1607 devices, because extended support ends on October 13, 2026
• Install the October 2026 security update on all supported Windows systems and verify the build against the MSRC KB for your edition
• Reduce local accounts and admin rights on kiosk, POS and HMI-type systems
• Monitor for unusual privilege escalation on critical hosts

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: CVE-2026-96312 msrc.microsoft.com
• OpenCVE: CVE-2026-96312 app.opencve.io
• 4sysops: Windows 10 Enterprise LTSB 2016 end of support and ESU 4sysops.com
• Insentra: Windows 10 LTSB is ending www.insentragroup.com

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 2 Nov 2026, 00:55.