Microsoft Windows Cryptographic Services: Use-after-free allows remote code execution

Summary

A use-after-free flaw (CWE-416) in Windows Cryptographic Services affects several supported and legacy Windows 10, Windows 11 and Windows Server versions. An authorized attacker with low privileges can exploit it over the network to execute code, with high impact on confidentiality, integrity and availability. The attack complexity is high, so exploitation requires specific conditions and a foothold on the target. CISA SSVC data lists no known exploitation.

Affected

• Windows 10 Version 1607 (10.0.14393.0 to before 10.0.14393.9612)
• Windows 10 Version 1809 (10.0.17763.0 to before 10.0.17763.9376)
• Windows 10 Version 21H2 (10.0.19044.0 to before 10.0.19044.7807)
• Windows 10 Version 22H2 (10.0.19045.0 to before 10.0.19045.7807)
• Windows 11 Version 23H2 (10.0.22631.0 to before 10.0.22631.7652)
• Windows 11 Version 24H2 (10.0.26100.0 to before 10.0.26100.9711)
• Windows 11 Version 25H2 (10.0.26200.0 to before 10.0.26200.9711)
• Windows 11 Version 26H1 (10.0.28000.0 to before 10.0.28000.3231)
• Windows 11 Version 26H2 (10.0.26300.0 to before 10.0.26300.9711)
• Windows Server 2012 and Server Core installation (6.2.9200.0 to before 6.2.9200.26434)
• Windows Server 2012 R2 and Server Core installation (6.3.9600.0 to before 6.3.9600.23470)
• Windows Server 2016 (10.0.14393.0 to before 10.0.14393.9612)

Fixed in

• Windows 10 Version 1607 and Windows Server 2016: build 10.0.14393.9612
• Windows 10 Version 1809: build 10.0.17763.9376
• Windows 10 Version 21H2: build 10.0.19044.7807
• Windows 10 Version 22H2: build 10.0.19045.7807
• Windows 11 Version 23H2: build 10.0.22631.7652
• Windows 11 Version 24H2 and 25H2, Windows 11 Version 26H2: build 10.0.26100.9711 and 10.0.26200.9711 and 10.0.26300.9711 respectively
• Windows 11 Version 26H1: build 10.0.28000.3231
• Windows Server 2012: build 6.2.9200.26434
• Windows Server 2012 R2: build 6.3.9600.23470

The KB numbers for Windows 10 1607 and Windows Server 2016 are unknown and must be taken from the Microsoft Security Update Guide.

Workaround

Unknown. No workaround or mitigation is documented in the sources reviewed. Apply the Microsoft security update.

Exploitation

• CISA SSVC: Exploitation none, Automatable no, Technical Impact total.
• CISA KEV: not listed.
• No public proof-of-concept exploit found in the sources reviewed.
• No exploitation reports found.

Our recommendation

• Inventory all Windows 10, Windows 11 and Windows Server systems and compare their builds with the fixed builds listed above.
• Install the October 2026 Microsoft security update on affected systems, starting with servers reachable from untrusted networks.
• Replace Windows 10 Version 1607 and Windows Server 2016 hosts if they are out of support, or isolate them until they are migrated.
• Monitor for exploitation activity and re-check CISA KEV and public exploit sources after the next update cycle.

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-2026-70014 msrc.microsoft.com
• NVD record via Vulners: CVE-2026-70014 vulners.com
• OpenCVE: CVE-2026-70014 app.opencve.io
• Strix: CVE-2026-70014 (Windows Server 2012 build) www.strix.ai
• SonicWall: Microsoft security bulletin coverage for October 2026 www.sonicwall.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, 19:13.