CVE-2026-40404
No known exploitation. EPSS puts it in the 27th percentile. Fixed versions are out.
No public exploit knownFix5 products10 fixed builds listed below
e.g. OID 1.3.6.1.4.1.25623.1.3.0.10816.0.5094122.494846484649525157514657505152
What to do
Find your product and version, then upgrade to the build on the right.
- Microsoft Windows 11 version 23H2Affected: ≥ 10.0.22631.0, < 10.0.22631.7219Upgrade to: 10.0.22631.7219Affected: ≥ 10.0.26100.0, < 10.0.26100.8655Upgrade to: 10.0.26100.8655Affected: ≥ 10.0.26200.0, < 10.0.26200.8655Upgrade to: 10.0.26200.8655Affected: ≥ 10.0.28000.0, < 10.0.28000.2269Upgrade to: 10.0.28000.2269Stated by: CVE record
- Microsoft Windows 10 Version 1607Affected: ≥ 10.0.14393.0, < 10.0.14393.9234Upgrade to: 10.0.14393.9234Affected: ≥ 10.0.17763.0, < 10.0.17763.8880Upgrade to: 10.0.17763.8880Affected: ≥ 10.0.19044.0, < 10.0.19044.7417Upgrade to: 10.0.19044.7417Affected: ≥ 10.0.19045.0, < 10.0.19045.7417Upgrade to: 10.0.19045.7417Stated by: CVE record
- Microsoft Windows Server 2025Affected: ≥ 10.0.26100.0, < 10.0.26100.32995Upgrade to: 10.0.26100.32995Stated by: CVE record
- Microsoft Windows Server 2022Affected: ≥ 10.0.20348.0, < 10.0.20348.5256Upgrade to: 10.0.20348.5256Stated by: CVE record
- Microsoft Windows Server 2019Affected: ≥ 10.0.17763.0, < 10.0.17763.8880Upgrade to: 10.0.17763.8880Stated by: CVE record
Versions as the sources state them. 3 more products have version data. Full version matrix after sign-in
What it is
From the CVE record
Windows Universal Disk Format File System Driver (UDFS) Elevation of Privilege Vulnerability
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.3% chance of exploitation activity in the next 30 days, which ranks it in the 27th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
8 events over 44 days, from the signal feeds we watch.
- Patch availablerecord updated
- OpenVAS check added
- Patch availablerecord updated
- Publishedweakness classified, att&ck mapped
Affected products
- Windows 11 version 23H2Operating Systems / windows
- Windows 10 Version 1607Operating Systems / windows
- Windows Server 2025 (Server Core installation)Operating Systems / windows
- Windows Server 2022 (Server Core installation)Operating Systems / windows
- Windows Server 2019 (Server Core installation)Operating Systems / windows
- Windows Server 2016 (Server Core installation)Operating Systems / windows
- Windows Server 2012 R2 (Server Core installation)Operating Systems / windows
- Windows Server 2012 (Server Core installation)Operating Systems / windows
And 45 more affected products. See all after sign-in
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Scored 7.8 by NVD.
How it is reached
- Attack Vector LocalRequires local access to the vulnerable system (e.g. local login, malicious file)
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required LowRequires basic user-level privileges
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality HighTotal information disclosure — all data in the component is compromised
- Integrity HighTotal loss of integrity — attacker can modify any data in the component
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
- Privilege EscalationT1068Exploitation for Privilege Escalationhigh confidence
Sources
Watch the software you run.
My Stack ranks new CVEs for your products by real-world exploitation, so the next serious one reaches you without reading every advisory.
We'll flag the next CVE, public exploit or patch for Windows 11 version 23H2, not every advisory.
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