Microsoft Windows FileCrypt Driver: Security feature bypass via improper access control

Summary

A flaw in the Windows FileCrypt Driver, a file system filter driver used for encryption, allows an authorized attacker to bypass a security feature. According to the CVSS vector, the attack is reachable over the network but requires high attack complexity and a valid low-privilege account, with no user interaction. The impact is limited to high confidentiality loss, with no integrity or availability impact. The specific bypassed security feature is not named in the sources.

Affected

• Windows 10 Version 1607 and Windows Server 2016 (including Server Core): builds 10.0.14393.0 before 10.0.14393.9688
• Windows 10 Version 1809 and Windows Server 2019 (including Server Core): builds 10.0.17763.0 before 10.0.17763.9487
• Windows 10 Version 21H2: builds 10.0.19044.0 before 10.0.19044.7846
• Windows 10 Version 22H2: builds 10.0.19045.0 before 10.0.19045.7846
• Windows 11 Version 23H2: builds 10.0.22631.0 before 10.0.22631.7711
• Windows 11 Version 24H2 and 25H2: builds before 10.0.26100.9974 and 10.0.26200.9974
• Windows 11 Version 26H1: builds before 10.0.28000.3501
• Windows 11 Version 26H2: builds before 10.0.26300.9974
• Windows Server 2022: builds 10.0.20348.0 before 10.0.20348.5870

Fixed in

• Install the November 10, 2026 Microsoft security update for the affected versions.
• Fixed builds per the CNA record: 10.0.19044.7846 (21H2), 10.0.22631.7711 (Windows 11 23H2).
• Verify the fixed build numbers in the MSRC Security Update Guide before relying on them.

Workaround

Unknown.

Exploitation

• No evidence of exploitation in the wild found.
• Microsoft exploitability assessment: Exploitation Less Likely, not publicly disclosed.
• No public proof of concept found.
• CISA SSVC: Exploitation none, Automatable no, technical impact partial.

Our recommendation

• Deploy the November 2026 cumulative update to Windows clients and servers in the regular update cycle.
• Verify build numbers after patching.
• Check ESU status on Windows 10 1607 and 1809 systems.
• Limit local and network logons to trusted accounts, since a valid low-privilege account is required.
• Confirm the final CVSS score and CWE on NVD, as the CWE value is not verified.

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

• MSRC Security Update Guide: CVE-2026-113756 msrc.microsoft.com
• CVE Record CVE-2026-113756 www.cve.org
• Strix: CVE-2026-113756 www.strix.ai
• Rapid7: Patch Tuesday November 2026 www.rapid7.com
• Anoop C Nair: Microsoft fixes 1235 security vulnerabilities www.anoopcnair.com
• VULDB entry 434904 (sibling CVE context) vuldb.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 11 Nov 2026, 18:33.