CVE-2026-40405: Microsoft Windows 11 Version 24H2 · NULL Pointer Dereference
Affects Microsoft Windows 11 Version 24H2Source CVE Database V5
Not known to be exploited · CVSS 7.5 High : upgrade to 10.0.26100.8457 soon.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 1.0% chance of exploitation in 30 days – higher than 64% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 10.0.26100.8457, 10.0.26200.8457, 10.0.28000.2113 +1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:CExploitation evidence
Disclosed: evidence found.
CVE published 12 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| MicrosoftWindows 11 Version 24H2 | Affected
| Fixed in
|
| MicrosoftWindows 11 Version 25H2 | Affected
| Fixed in
|
| MicrosoftWindows 11 version 26H1 | Affected
| Fixed in
|
| MicrosoftWindows Server 2025 | Affected
| Fixed in
|
| MicrosoftWindows Server 2025 (Server Core installation) | Affected
| Fixed in
|
AI-suggested
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.
Description
Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service over a network.