Windows Cloud Files Mini Filter Driver: Race condition enables privilege escalation
Summary
A time-of-check time-of-use (TOCTOU) race condition in the Windows Cloud Files Mini Filter Driver (cldflt.sys) allows an authorized local user to elevate privileges. The driver is present on most Windows installations because of OneDrive and similar sync clients. An attacker needs a local account or local code execution, which they could obtain through phishing, a malicious application or a compromised user account. Exploitation is not known and the CVSS score is 7.0 (High).
Affected
- 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 2019 and Server Core installation (before 10.0.17763.9487)
- Windows Server 2022 (before 10.0.20348.5870)
- Windows Server 2025 and Server Core installation (before 10.0.26100.33822)
Fixed in
- Fixed in the November 2026 security updates (per the Microsoft CNA record and the affected build ranges above).
- Per-product KB numbers: Unknown. Confirm in the MSRC Security Update Guide.
Workaround
- No vendor workaround known.
- Disabling the Cloud Files driver may affect system features and is not recommended as a substitute for patching.
Exploitation
- Exploitation in the wild: No evidence found.
- CISA SSVC: Exploitation none, not automatable, total technical impact.
- CVSS temporal exploit maturity: unproven.
- Related but different: CVE-2025-62221 (use-after-free in the same driver) was confirmed as exploited.
Our recommendation
- Deploy the November 2026 cumulative updates to all affected Windows 10, Windows 11 and Windows Server systems, prioritising multi-user systems, RDP or terminal servers and file servers.
- Verify patch levels with your RMM tool or WSUS, and include machines where OneDrive is used.
- Monitor NVD and CISA KEV for changes in exploitation status.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Windows Cloud Files Mini Filter Driver
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5131085, KB5131096, KB5131090, KB5131087, KB5132061, KB5132043
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-112810 msrc.microsoft.com
- CVE Record CVE-2026-112810 www.cve.org
- Tenable: November 2026 Patch Tuesday www.tenable.com
- Strix aggregator entry for CVE-2026-112810 www.strix.ai
- Windows Cloud Files zero-day overview (Cybersecurity News) cybersecuritynews.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, 09:11.
Original description (NVD)
Time-of-check time-of-use (toctou) race condition in Windows Cloud Files Mini Filter Driver allows an authorized attacker to elevate privileges locally.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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