CVE-2026-40405: CWE-476: NULL Pointer Dereference in Microsoft Windows 11 Version 24H2
Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service over a network.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-40405) affects Windows 11 Version 24H2 (build 10.0.26100.0) and is classified as CWE-476: NULL Pointer Dereference. It occurs in the Windows TCP/IP implementation, where an attacker can send specially crafted network traffic to cause the system to dereference a null pointer, leading to a denial of service condition. The CVSS v3.1 base score is 7.5, reflecting network attack vector, no privileges or user interaction required, and a high impact on availability. Microsoft has released an official patch to remediate this vulnerability.
Potential Impact
Successful exploitation results in denial of service by crashing or destabilizing the affected Windows 11 system's network stack. There is no impact on confidentiality or integrity. No known exploits are reported in the wild at this time.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security update provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40405 to remediate this vulnerability. No additional mitigation actions are indicated by the vendor.
CVE-2026-40405: CWE-476: NULL Pointer Dereference in Microsoft Windows 11 Version 24H2
Description
Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service over a network.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-40405) affects Windows 11 Version 24H2 (build 10.0.26100.0) and is classified as CWE-476: NULL Pointer Dereference. It occurs in the Windows TCP/IP implementation, where an attacker can send specially crafted network traffic to cause the system to dereference a null pointer, leading to a denial of service condition. The CVSS v3.1 base score is 7.5, reflecting network attack vector, no privileges or user interaction required, and a high impact on availability. Microsoft has released an official patch to remediate this vulnerability.
Potential Impact
Successful exploitation results in denial of service by crashing or destabilizing the affected Windows 11 system's network stack. There is no impact on confidentiality or integrity. No known exploits are reported in the wild at this time.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security update provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40405 to remediate this vulnerability. No additional mitigation actions are indicated by the vendor.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-04-13T00:27:50.798Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40405","vendor":"Microsoft"}]
Threat ID: 6a036557cbff5d861008c9bb
Added to database: 5/12/2026, 5:37:27 PM
Last enriched: 5/12/2026, 6:24:01 PM
Last updated: 5/13/2026, 4:49:49 AM
Views: 2
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
External Links
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.