CVE-2026-40409
HIGH 7.8Windows Universal Disk Format File System Driver (UDFS) Elevation of Privilege Vulnerability
ELEVATED IMPACT
Severe if exploited (CVSS 7.8), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.3%chance of exploitation in 30 days · 22nd percentile
○ In CISA KEV
○ Public exploit / PoC
Impact if exploited
7.8CVSS 3.1 · HIGH
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ⚠Access: Requires local access to the host
- ⚠Privileges: Requires a low-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Affected
Vendors Microsoft
Products Windows 10 Version 1607 Windows 10 Version 1809 Windows 10 Version 21h2 Windows 10 Version 22h2 Windows 11 Version 23h2 Windows 11 Version 24h2 Windows 11 Version 25h2 Windows 11 Version 26h1
Weakness (CWE)
- CWE-197
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C