CVE-2026-40405

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-40405", "assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "state": "PUBLISHED", "assignerShortName": "microsoft", "dateReserved": "2026-04-13T00:27:50.798Z", "datePublished": "2026-05-12T16:58:42.545Z", "dateUpdated": "2026-08-10T15:12:54.079Z"}, "containers": {"cna": {"title": "Windows TCP/IP Denial of Service Vulnerability", "datePublic": "2026-05-12T14:00:00.000Z", "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*", "versionStartIncluding": "10.0.26100.0", "versionEndExcluding": "10.0.26100.32860"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_25H2:*:*:*:*:*:*:arm64:*", "versionStartIncluding": "10.0.26200.0", "versionEndExcluding": "10.0.26200.8457"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_24H2:*:*:*:*:*:*:arm64:*", "versionStartIncluding": "10.0.26100.0", "versionEndExcluding": "10.0.26100.8457"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*", "versionStartIncluding": "10.0.26100.0", "versionEndExcluding": "10.0.26100.32860"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_26H1:*:*:*:*:*:*:x64:*", "versionStartIncluding": "10.0.28000.0", "versionEndExcluding": "10.0.28000.2113"}]}]}], "affected": [{"vendor": "Microsoft", "product": "Windows 11 Version 24H2", "platforms": ["ARM64-based Systems", "x64-based Systems"], "versions": [{"version": "10.0.26100.0", "lessThan": "10.0.26100.8457", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows 11 Version 25H2", "platforms": ["ARM64-based Systems", "x64-based Systems"], "versions": [{"version": "10.0.26200.0", "lessThan": "10.0.26200.8457", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows 11 version 26H1", "platforms": ["ARM64-based Systems", "x64-based Systems"], "versions": [{"version": "10.0.28000.0", "lessThan": "10.0.28000.2113", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2025", "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.26100.0", "lessThan": "10.0.26100.32860", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2025 (Server Core installation)", "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.26100.0", "lessThan": "10.0.26100.32860", "versionType": "custom", "status": "affected"}]}], "descriptions": [{"value": "Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service over a network.", "lang": "en-US"}], "problemTypes": [{"descriptions": [{"description": "CWE-476: NULL Pointer Dereference", "lang": "en-US", "type": "CWE", "cweId": "CWE-476"}]}], "providerMetadata": {"orgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "shortName": "microsoft", "dateUpdated": "2026-08-10T15:12:54.079Z"}, "references": [{"name": "Windows TCP/IP Denial of Service Vulnerability", "tags": ["vendor-advisory", "patch"], "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40405"}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en-US", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "baseSeverity": "HIGH", "baseScore": 7.5, "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C"}}]}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-05-12T19:32:05.488535Z", "id": "CVE-2026-40405", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-05-12T19:32:22.466Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-40405", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-05-12T19:32:05.488535Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-05-12T19:32:13.688Z"}}], "cna": {"title": "Windows TCP/IP Denial of Service Vulnerability", "metrics": [{"format": "CVSS", "cvssV3_1": {"version": "3.1", "baseScore": 7.5, "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C"}, "scenarios": [{"lang": "en-US", "value": "GENERAL"}]}], "affected": [{"vendor": "Microsoft", "product": "Windows 11 Version 24H2", "versions": [{"status": "affected", "version": "10.0.26100.0", "lessThan": "10.0.26100.8457", "versionType": "custom"}], "platforms": ["ARM64-based Systems", "x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows 11 Version 25H2", "versions": [{"status": "affected", "version": "10.0.26200.0", "lessThan": "10.0.26200.8457", "versionType": "custom"}], "platforms": ["ARM64-based Systems", "x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows 11 version 26H1", "versions": [{"status": "affected", "version": "10.0.28000.0", "lessThan": "10.0.28000.2113", "versionType": "custom"}], "platforms": ["ARM64-based Systems", "x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2025", "versions": [{"status": "affected", "version": "10.0.26100.0", "lessThan": "10.0.26100.32860", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2025 (Server Core installation)", "versions": [{"status": "affected", "version": "10.0.26100.0", "lessThan": "10.0.26100.32860", "versionType": "custom"}], "platforms": ["x64-based Systems"]}], "datePublic": "2026-05-12T14:00:00.000Z", "references": [{"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40405", "name": "Windows TCP/IP Denial of Service Vulnerability", "tags": ["vendor-advisory", "patch"]}], "descriptions": [{"lang": "en-US", "value": "Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service over a network."}], "problemTypes": [{"descriptions": [{"lang": "en-US", "type": "CWE", "cweId": "CWE-476", "description": "CWE-476: NULL Pointer Dereference"}]}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "10.0.26100.32860", "versionStartIncluding": "10.0.26100.0"}, {"criteria": "cpe:2.3:o:microsoft:windows_11_25H2:*:*:*:*:*:*:arm64:*", "vulnerable": true, "versionEndExcluding": "10.0.26200.8457", "versionStartIncluding": "10.0.26200.0"}, {"criteria": "cpe:2.3:o:microsoft:windows_11_24H2:*:*:*:*:*:*:arm64:*", "vulnerable": true, "versionEndExcluding": "10.0.26100.8457", "versionStartIncluding": "10.0.26100.0"}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "10.0.26100.32860", "versionStartIncluding": "10.0.26100.0"}, {"criteria": "cpe:2.3:o:microsoft:windows_11_26H1:*:*:*:*:*:*:x64:*", "vulnerable": true, "versionEndExcluding": "10.0.28000.2113", "versionStartIncluding": "10.0.28000.0"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "shortName": "microsoft", "dateUpdated": "2026-06-19T16:12:20.605Z"}}}, "cveMetadata": {"cveId": "CVE-2026-40405", "state": "PUBLISHED", "dateUpdated": "2026-06-19T16:12:20.605Z", "dateReserved": "2026-04-13T00:27:50.798Z", "assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "datePublished": "2026-05-12T16:58:42.545Z", "assignerShortName": "microsoft"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"platforms": ["ARM64-based Systems", "x64-based Systems"], "product": "Windows 11 Version 24H2", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.26100.8457", "status": "affected", "version": "10.0.26100.0", "versionType": "custom"}]}, {"platforms": ["ARM64-based Systems", "x64-based Systems"], "product": "Windows 11 Version 25H2", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.26200.8457", "status": "affected", "version": "10.0.26200.0", "versionType": "custom"}]}, {"platforms": ["ARM64-based Systems", "x64-based Systems"], "product": "Windows 11 version 26H1", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.28000.2113", "status": "affected", "version": "10.0.28000.0", "versionType": "custom"}]}, {"platforms": ["x64-based Systems"], "product": "Windows Server 2025", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.26100.32860", "status": "affected", "version": "10.0.26100.0", "versionType": "custom"}]}, {"platforms": ["x64-based Systems"], "product": "Windows Server 2025 (Server Core installation)", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.26100.32860", "status": "affected", "version": "10.0.26100.0", "versionType": "custom"}]}], "source": "secure@microsoft.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:*", "matchCriteriaId": "048AD3CD-DD62-4B62-9302-61779D998B4A", "versionEndExcluding": "10.0.26100.8390", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:*", "matchCriteriaId": "3682F4DD-0870-4E39-B75E-649C89BB1E08", "versionEndExcluding": "10.0.26100.8390", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:*", "matchCriteriaId": "C2C93D38-DFD7-4DE1-95B8-6D73E4A545D6", "versionEndExcluding": "10.0.26200.8390", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:*", "matchCriteriaId": "05EB89A0-2ADD-4B67-A644-41FE1DE69E4A", "versionEndExcluding": "10.0.26200.8390", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:arm64:*", "matchCriteriaId": "D45A5D2F-E058-4033-B184-BAE224FC1CEA", "versionEndExcluding": "10.0.28000.2113", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:x64:*", "matchCriteriaId": "5127F350-9271-4B74-84E0-D7E5D2D5640E", "versionEndExcluding": "10.0.28000.2113", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*", "matchCriteriaId": "9ABAB3B9-28AF-4278-8E78-E1191B1AFC0C", "versionEndExcluding": "10.0.26100.32772", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service over a network."}, {"lang": "es", "value": "Desreferencia de puntero nulo en Windows TCP/IP permite a un atacante no autorizado denegar el servicio a trav\u00e9s de una red."}], "id": "CVE-2026-40405", "lastModified": "2026-11-11T20:10:00.273", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "secure@microsoft.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-40405", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-05-12T19:32:05.488535Z", "version": "2.0.3"}}]}, "published": "2026-05-12T18:17:18.310", "references": [{"source": "secure@microsoft.com", "tags": ["Vendor Advisory"], "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40405"}], "sourceIdentifier": "secure@microsoft.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-476"}], "source": "secure@microsoft.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": ["arm64-based_systems", "x64-based_systems"], "status": "affected", "versions": {"scheme": "generic", "value": "[10.0.26100.0,10.0.26100.8457)"}}], "enrichment": {"confidence": 86.0, "confidence_source": "matching", "scores": [{"score": 86.0, "source": "matching"}]}, "original": {"product": "Windows 11 Version 24H2", "source": "cna", "vendor": "Microsoft"}, "product": "windows_11_24h2", "vendor": "microsoft"}, {"configurations": [{"platform": ["arm64-based_systems", "x64-based_systems"], "status": "affected", "versions": {"scheme": "generic", "value": "[10.0.26200.0,10.0.26200.8457)"}}], "enrichment": {"confidence": 86.0, "confidence_source": "matching", "scores": [{"score": 86.0, "source": "matching"}]}, "original": {"product": "Windows 11 Version 25H2", "source": "cna", "vendor": "Microsoft"}, "product": "windows_11_25h2", "vendor": "microsoft"}, {"configurations": [{"platform": ["arm64-based_systems", "x64-based_systems"], "status": "affected", "versions": {"scheme": "generic", "value": "[10.0.28000.0,10.0.28000.2113)"}}], "enrichment": {"confidence": 86.0, "confidence_source": "matching", "scores": [{"score": 86.0, "source": "matching"}]}, "original": {"product": "Windows 11 version 26H1", "source": "cna", "vendor": "Microsoft"}, "product": "windows_11_26h1", "vendor": "microsoft"}, {"configurations": [{"platform": ["x64-based_systems"], "status": "affected", "versions": {"scheme": "generic", "value": "[10.0.26100.0,10.0.26100.32860)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Windows Server 2025", "source": "cna", "vendor": "Microsoft"}, "product": "windows_server_2025", "vendor": "microsoft"}, {"configurations": [{"platform": ["x64-based_systems"], "status": "affected", "versions": {"scheme": "generic", "value": "[10.0.26100.0,10.0.26100.32860)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Windows Server 2025 (Server Core installation)", "source": "cna", "vendor": "Microsoft"}, "product": "windows_server_2025_(server_core_installation)", "vendor": "microsoft"}], "created": "2026-05-12T19:30:23.354782+00:00", "updated": "2026-05-13T10:00:10.934964+00:00", "vendors": ["microsoft", "microsoft$PRODUCT$windows_11_24h2", "microsoft$PRODUCT$windows_11_25h2", "microsoft$PRODUCT$windows_11_26h1", "microsoft$PRODUCT$windows_server_2025", "microsoft$PRODUCT$windows_server_2025_(server_core_installation)"]}