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PatchSiren cyber security CVE debrief

CVE-2026-40404 Microsoft CVE debrief

CVE-2026-40404 is a HIGH severity Elevation of Privilege vulnerability in the Windows Universal Disk Format File System Driver (UDFS). The vulnerability has a CVSS score of 7.8 and was published on 2026-06-09T17:17:06.240Z. The vulnerability affects multiple versions of Windows 10, Windows 11, and Windows Server.

Vendor
Microsoft
Product
Windows 10 Version 1607
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-09
Original CVE updated
2026-06-10
Advisory published
2026-06-09
Advisory updated
2026-06-10

Who should care

Administrators and users of affected Windows systems should apply patches to mitigate this vulnerability.

Technical summary

The vulnerability is caused by a weakness in the Windows Universal Disk Format File System Driver (UDFS). Successful exploitation of this vulnerability could allow an attacker to elevate their privileges on a vulnerable system.

Defensive priority

HIGH

Recommended defensive actions

  • Apply patches from Microsoft as soon as possible.
  • See ${ref-4} for vendor advisory.

Evidence notes

The CVE record ${cve-org} and NVD detail ${nvd} provide additional information about this vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-40404 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-40404

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-40404 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-40404

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.