CVE-2026-40405 json
Windows TCP/IP Denial of Service Vulnerability
published 2026-05-12 5 mo ago modified 2026-08-10 2 mo ago also EUVD-2026-29665
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.1%
- EPSS 1.1% chance of exploitation in 30 days, percentile 65%
- public exploits
- 0
- none known
Summary
Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service over a network.
Patch / fix
- Microsoft Windows 11 Version 24H2 10.0.26100.8457
- Microsoft Windows 11 Version 25H2 10.0.26200.8457
- Microsoft Windows 11 version 26H1 10.0.28000.2113
- Microsoft Windows Server 2025 10.0.26100.32860
- Microsoft Windows Server 2025 (Server Core installation) 10.0.26100.32860
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 5 mo ago
Exploit prediction
1.08% chance of exploitation in the next 30 days, higher than 65% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C |
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Affected products
- Microsoft Windows 11 Version 24H2
- Microsoft Windows 11 Version 25H2
- Microsoft Windows 11 version 26H1
- Microsoft Windows Server 2025
- Microsoft Windows Server 2025 (Server Core installation)
Classification
- Weakness
-
- CWE-476 NULL Pointer Dereference
References
-
msrc.microsoft.com
/update-guide/vulnerability/CVE-2026-40405
vendor-advisory, patch
Sources
- CVE List CVE-2026-40405
- NVD CVE-2026-40405
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