NULL pointer dereference in Microsoft Windows 11 24h2
CVE-2026-40405
Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service over a network.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.012 (66.3th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 66th percentile — 66.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.011 · newest: 0.012 · change: +0.001
Affected products
- Microsoft Windows 11 24h2
- Microsoft Windows 11 25h2
- Microsoft Windows 11 26h1
- Microsoft Windows 11 Version 24h2 — versions 10.0.26100.0
- Microsoft Windows 11 Version 25h2 — versions 10.0.26200.0
- Microsoft Windows 11 Version 26h1 — versions 10.0.28000.0
- Microsoft Windows Server 2025 — versions 10.0.26100.0
- Microsoft Windows Server 2025
- Microsoft Windows Server 2025 (Server Core Installation) — versions 10.0.26100.0
Weakness classification (CWE)
References
- Windows TCP/IP Denial of Service Vulnerability (vendor-advisory, patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-40405?
- CVE-2026-40405 is a high-severity vulnerability in Microsoft Windows 11 24h2, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2026-05-12.
- How severe is CVE-2026-40405?
- High severity. CVSS v3 base score is 7.5 out of 10.