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TI-2026-29173 Aliases CVE-2026-40405GHSA-mj3g-9j9x-c556

Windows TCP/IP Denial of Service Vulnerability

Priority MEDIUM 41CWE-476Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Microsoft. Impact type from Microsoft.

Summary

Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service over a network.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01078 65th percentileScored 2026-11-07
Fix Fixed Microsoft: 5 updates

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MicrosoftWindows 11 Version 24H210.0.26100.0 to before 10.0.26100.845710.0.26100.8457Patch availableCNA
MicrosoftWindows 11 Version 25H210.0.26200.0 to before 10.0.26200.845710.0.26200.8457Patch availableCNA
MicrosoftWindows 11 version 26H110.0.28000.0 to before 10.0.28000.211310.0.28000.2113Patch availableCNA
MicrosoftWindows Server 202510.0.26100.0 to before 10.0.26100.3286010.0.26100.32860Patch availableCNA
MicrosoftWindows Server 2025 (Server Core installation)10.0.26100.0 to before 10.0.26100.3286010.0.26100.32860Patch availableCNA
  • Windows 11 Version 24H2 VendorMicrosoft Affected 10.0.26100.0 to before 10.0.26100.8457 Fixed in 10.0.26100.8457 Patch available CNA
  • Windows 11 Version 25H2 VendorMicrosoft Affected 10.0.26200.0 to before 10.0.26200.8457 Fixed in 10.0.26200.8457 Patch available CNA
  • Windows 11 version 26H1 VendorMicrosoft Affected 10.0.28000.0 to before 10.0.28000.2113 Fixed in 10.0.28000.2113 Patch available CNA
  • Windows Server 2025 VendorMicrosoft Affected 10.0.26100.0 to before 10.0.26100.32860 Fixed in 10.0.26100.32860 Patch available CNA
  • Windows Server 2025 (Server Core installation) VendorMicrosoft Affected 10.0.26100.0 to before 10.0.26100.32860 Fixed in 10.0.26100.32860 Patch available CNA

CPE configurations NVD · 7

CPEVersionsRoleVendor
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:*before 10.0.26100.8390VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:*before 10.0.26100.8390VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:*before 10.0.26200.8390VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:*before 10.0.26200.8390VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:arm64:*before 10.0.28000.2113VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:x64:*before 10.0.28000.2113VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*before 10.0.26100.32772VulnerableMicrosoft
  • cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:* Versions before 10.0.26100.8390 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:* Versions before 10.0.26100.8390 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:* Versions before 10.0.26200.8390 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:* Versions before 10.0.26200.8390 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:arm64:* Versions before 10.0.28000.2113 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:x64:* Versions before 10.0.28000.2113 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:* Versions before 10.0.26100.32772 Vulnerable ·Microsoft

Remediation

Microsoft 5 updates

  • KB5089549
    Security Update
    • Windows 11 Version 24H2 for ARM64-based Systems 10.0.26100.8457
    • Windows 11 Version 24H2 for x64-based Systems 10.0.26100.8457
    • Windows 11 Version 25H2 for ARM64-based Systems 10.0.26200.8457
    • Windows 11 Version 25H2 for x64-based Systems 10.0.26200.8457
  • KB5089548
    Security Update
    • Windows 11 Version 26H1 for ARM64-based Systems 10.0.28000.2113
    • Windows 11 version 26H1 for x64-based Systems 10.0.28000.2113
  • KB5089466
    Security Hotpatch Update
    • Windows 11 Version 24H2 for ARM64-based Systems 10.0.26100.8390
    • Windows 11 Version 24H2 for x64-based Systems 10.0.26100.8390
    • Windows 11 Version 25H2 for ARM64-based Systems 10.0.26200.8390
    • Windows 11 Version 25H2 for x64-based Systems 10.0.26200.8390
Show 2 more Microsoft updates
  • KB5087539
    Security Update
    • Windows Server 2025 10.0.26100.32860
    • Windows Server 2025 (Server Core installation) 10.0.26100.32860
  • KB5087423
    Security Hotpatch Update
    • Windows Server 2025 10.0.26100.32772
    • Windows Server 2025 (Server Core installation) 10.0.26100.32772

Vendor assessments

Microsoft

Microsoft's page for this CVE →

Impact
Denial of Service
Exploited
No
Publicly disclosed
No
Exploitability
Exploitation Less Likely

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-40405
  2. 2026-10-03 Alias added: GHSA-mj3g-9j9x-c556

References

Patch 1

  • TI-2026-26194 Windows Internet Key Exchange (IKE) Service Extensions Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-73128 Windows Shell Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 8.8
  • TI-2026-17367 MSHTML Framework Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 8.8
  • TI-2026-17364 Windows Shell Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 8.8
  • TI-2025-24062 Windows SMB Client Elevation of Privilege Vulnerability KEVCVSS 3.1HIGH 8.8
  • TI-2025-24042 Internet Shortcut Files Remote Code Execution Vulnerability KEVCVSS 3.1HIGH 8.8
See all 3558 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences