Microsoft Windows: Information disclosure in Cloud Files Mini Filter Driver
Summary
The Windows Cloud Files Mini Filter Driver (cldflt.sys) contains an improper access control flaw (CWE-424) that allows an authorized local user to read information they should not see. The attacker needs a local, low-privilege account and no user interaction, and the impact is limited to confidentiality. The main risk is that the flaw can serve as a step in a multi-stage attack.
Affected
- Windows 10 Version 1809 (builds before 10.0.17763.9487)
- Windows 10 Version 21H2 (builds before 10.0.19044.7846)
- Windows 10 Version 22H2 (builds before 10.0.19045.7846)
- Windows 11 Version 23H2 (builds before 10.0.22631.7711)
- Windows 11 Version 24H2 (builds before 10.0.26100.9974)
- Windows 11 Version 25H2 (builds before 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 2019, including Server Core (builds before 10.0.17763.9487)
- Windows Server 2022 (builds before 10.0.20348.5870)
- Windows Server 2025, including Server Core (builds before 10.0.26100.33822)
Fixed in
- Install the Microsoft security update of November 2026 (Patch Tuesday, 10 November 2026) or a later cumulative update for your Windows version.
- Fixed builds: see the affected build list. The exact KB number per build must be taken from the MSRC Security Update Guide.
Workaround
Unknown.
Exploitation
- No confirmed in-the-wild exploitation at the time of research.
- No public proof-of-concept exploit found.
- Rapid7 rates exploitation as less likely.
- CISA SSVC: exploitation none, not automatable, partial technical impact.
Our recommendation
- Include the November 2026 cumulative update in standard patching, with priority on hosts with local user access, shared Windows systems and RDS/terminal servers.
- Check whether Windows 10 1809 and Server 2019 are still supported in your environment and plan their replacement or upgrade if not.
- Monitor the MSRC advisory for changes in exploitation status or a published workaround.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Information disclosure – 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-2026-112803 msrc.microsoft.com
- CVE Record: CVE-2026-112803 www.cve.org
- Rapid7: Patch Tuesday November 2026 www.rapid7.com
- Senserva: KB5131085 senserva.com
- Strix.ai: CVE-2026-112803 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, 16:54.
Original description (NVD)
Improper access control in Windows Cloud Files Mini Filter Driver allows an authorized attacker to disclose information 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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