CVE-2026-42980
HIGH 7.8Integer underflow (wrap or wraparound) in Windows NT OS Kernel allows an authorized attacker to elevate privileges locally.
ELEVATED IMPACT
Severe if exploited (CVSS 7.8), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
5.7%chance of exploitation in 30 days · 92nd 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-191
- CWE-122
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