CVE-2026-40405
Windows TCP/IP Denial of Service Vulnerability
HIGH
7.5
CVSS Score
Published: May 12, 2026 at 04:58 PM UTC
Updated: June 17, 2026 at 10:45 AM UTC
4 products affected across 1 vendorWindows Server 2025Windows 11 24H2Windows 11 25H2
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Severity
HIGH7.5
Exploit prediction
EPSS 1%
SSVC
No known exploit
Description
Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service over a network.
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
Affected range stops below 10.0.26100.8457, so it looks safe — our inference, not a vendor statement
Affected range stops below 10.0.26200.8457, so it looks safe — our inference, not a vendor statement
Affected range stops below 10.0.28000.2113, so it looks safe — our inference, not a vendor statement
Affected range stops below 10.0.26100.32860, so it looks safe — our inference, not a vendor statement
Remediation
No guide yetNo remediation guidance has been written for this CVE yet. What the record does show:
Patch and advisory references
References (1)
Vendor AdvisoryPatch
Source: cverecord
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40405SSVC — Action Prioritization
SSVCNo known exploitAutomatablePartial impact
SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.
CVSS
7.5HIGHmicrosoft
Vector?
Quick Info
StatusANALYZED
CWE
CWE-476
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