ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2026-40409

Numeric truncation error in Windows Universal Disk Format File System Driver (UDFS) allows an authorized attacker to elevate privileges locally.

Published Jun 9, 2026 · catalog updated Nov 11, 2026 · windows 10 1607

Last checked Nov 11, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-40409. EPSS is 0.30%. Act only if a listed version of windows 10 1607 is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
High7.8
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.30%
Remediation
Version ranges on file
Affected products
cpe microsoft/windows 10 1607 · cpe microsoft/windows 10 1809 · cpe microsoft/windows 10 21h2 · cpe microsoft/windows 10 22h2

Numeric truncation error in Windows Universal Disk Format File System Driver (UDFS) allows an authorized attacker to elevate privileges locally.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe microsoft/windows 10 1607< 10.0.14393.9234
  • cpe microsoft/windows 10 1809< 10.0.17763.8880
  • cpe microsoft/windows 10 21h2< 10.0.19044.7417
  • cpe microsoft/windows 10 22h2< 10.0.19045.7417

How to fix CVE-2026-40409

  • Upgrade

    CVE-2026-40409 lists a fix boundary at 10.0.14393.9234. Compare the installed build with that boundary before you change production.

  • Version check

    Affected < 10.0.14393.9234

  • Advisory

    Open the nvd record and follow its fix.

  • Official advisories

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-40409. EPSS is 0.30%. Act only if a listed version of windows 10 1607 is installed.

Which versions are affected?

Compare what you have installed with microsoft/windows 10 1607 < 10.0.14393.9234; microsoft/windows 10 1809 < 10.0.17763.8880; microsoft/windows 10 21h2 < 10.0.19044.7417; microsoft/windows 10 22h2 < 10.0.19045.7417. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-197. EPSS 0.30%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Windows security

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Jun 9, 2026 · NIST NVD

    Detected

    Numeric truncation error in Windows Universal Disk Format File System Driver (UDFS) allows an authorized attacker to elevate privileges locally.

  2. Nov 11, 2026 · NIST NVD

    Updated

    Numeric truncation error in Windows Universal Disk Format File System Driver (UDFS) allows an authorized attacker to elevate privileges locally.

Sources

  • NIST NVDVulnerability recordCVE-2026-40409

    Numeric truncation error in Windows Universal Disk Format File System Driver (UDFS) allows an authorized attacker to elevate privileges locally.

    nvd.nist.gov

References

Freshness

Last verified in this catalog Nov 11, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • NIST NVDNov 11, 2026