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.
EPSS: 0.001 (35.1th percentile) — read the EPSS interpretation.
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.
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.