CVE-2026-40401 | Windows TCP/IP Denial of Service Vulnerability

Windows TCP/IP Denial of Service Vulnerability

Published: 2026-05-12 Last update: 2026-06-01 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-40401 is rated Low Risk (37.3/100): CVSS High severity, with low exploitation likelihood (EPSS 0.33%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-40401

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.05% 0.33% +0.28%
2 2026-06-13 0.05% 0.05% +0.01%
3 2026-05-18 — 0.05% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-40401

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.1 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.5 4.0 [email protected]

Weakness enumeration for CVE-2026-40401

GitHub Security Advisory for CVE-2026-40401

GHSA-8788-537q-vr5m · Severity: high — Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service locally.

Affected software / configurations for CVE-2026-40401

Vendor Product Version Raw CPE
microsoft windows_10_1607 < 10.0.14393.9140 cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*
microsoft windows_10_1809 < 10.0.17763.8755 cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*
microsoft windows_10_21h2 < 10.0.19044.7291 cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x64:*
microsoft windows_10_22h2 < 10.0.19045.7291 cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x64:*
microsoft windows_11_23h2 < 10.0.22631.7079 cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:*
microsoft windows_11_23h2 < 10.0.22631.7079 cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:*
microsoft windows_11_24h2 < 10.0.26100.8390 cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:*
microsoft windows_11_24h2 < 10.0.26100.8390 cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:*
microsoft windows_11_25h2 < 10.0.26200.8390 cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:*
microsoft windows_11_25h2 < 10.0.26200.8390 cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:*
microsoft windows_11_26h1 < 10.0.28000.2113 cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:arm64:*
microsoft windows_11_26h1 < 10.0.28000.2113 cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:x64:*
microsoft windows_server_2012 — cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
microsoft windows_server_2012 r2 cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
microsoft windows_server_2016 < 10.0.14393.9140 cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
microsoft windows_server_2019 < 10.0.17763.8755 cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
microsoft windows_server_2022 < 10.0.20348.5074 cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*
microsoft windows_server_2022_23h2 < 10.0.25398.2330 cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:*:*
microsoft windows_server_2025 < 10.0.26100.32772 cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*

References for CVE-2026-40401

cvelogic Threat Intelligence