CVE-2026-47291
CRITICAL 9.8Integer overflow or wraparound in Windows HTTP.sys allows an unauthorized attacker to execute code over a network.
LIKELY TARGET
21.5% modeled chance of exploitation in the next 30 days (97th percentile). Prioritize remediation.
Exploitation likelihood
21.5%chance of exploitation in 30 days · 97th percentile
○ In CISA KEV
○ Public exploit / PoC
Impact if exploited
9.8CVSS 3.1 · CRITICAL
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ✓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-190: Integer overflow
- CWE-122
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C