{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-88099", "assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "state": "PUBLISHED", "assignerShortName": "microsoft", "dateReserved": "2026-09-09T21:51:51.953Z", "datePublished": "2026-10-13T19:00:20.593Z", "dateUpdated": "2026-10-16T23:19:35.416Z"}, "containers": {"cna": {"title": "Windows Failover Cluster Denial of Service Vulnerability", "datePublic": "2026-10-13T14:00:00.000Z", "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*", "versionStartIncluding": "10.0.17763.0", "versionEndExcluding": "10.0.17763.9376"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*", "versionStartIncluding": "10.0.17763.0", "versionEndExcluding": "10.0.17763.9376"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*", "versionStartIncluding": "10.0.20348.0", "versionEndExcluding": "10.0.20348.5761"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*", "versionStartIncluding": "10.0.26100.0", "versionEndExcluding": "10.0.26100.33650"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*", "versionStartIncluding": "10.0.26100.0", "versionEndExcluding": "10.0.26100.33650"}]}]}], "affected": [{"vendor": "Microsoft", "product": "Windows Server 2019", "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.17763.0", "lessThan": "10.0.17763.9376", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2019 (Server Core installation)", "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.17763.0", "lessThan": "10.0.17763.9376", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2022", "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.20348.0", "lessThan": "10.0.20348.5761", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2025", "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.26100.0", "lessThan": "10.0.26100.33650", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2025 (Server Core installation)", "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.26100.0", "lessThan": "10.0.26100.33650", "versionType": "custom", "status": "affected"}]}], "descriptions": [{"value": "Uncaught exception in Windows Failover Cluster allows an unauthorized attacker to deny service over a network.", "lang": "en-US"}], "problemTypes": [{"descriptions": [{"description": "CWE-248: Uncaught Exception", "lang": "en-US", "type": "CWE", "cweId": "CWE-248"}]}], "providerMetadata": {"orgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "shortName": "microsoft", "dateUpdated": "2026-10-16T23:19:35.416Z"}, "references": [{"name": "Windows Failover Cluster Denial of Service Vulnerability", "tags": ["vendor-advisory", "patch"], "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88099"}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en-US", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "baseSeverity": "MEDIUM", "baseScore": 5.9, "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C"}}]}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-88099", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-13T19:58:10.343167Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-13T20:02:37.556Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-88099", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-13T19:58:10.343167Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-13T19:58:11.012Z"}}], "cna": {"title": "Windows Failover Cluster Denial of Service Vulnerability", "metrics": [{"format": "CVSS", "cvssV3_1": {"version": "3.1", "baseScore": 5.9, "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:H/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 Server 2019", "versions": [{"status": "affected", "version": "10.0.17763.0", "lessThan": "10.0.17763.9376", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2019 (Server Core installation)", "versions": [{"status": "affected", "version": "10.0.17763.0", "lessThan": "10.0.17763.9376", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2022", "versions": [{"status": "affected", "version": "10.0.20348.0", "lessThan": "10.0.20348.5761", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2025", "versions": [{"status": "affected", "version": "10.0.26100.0", "lessThan": "10.0.26100.33650", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2025 (Server Core installation)", "versions": [{"status": "affected", "version": "10.0.26100.0", "lessThan": "10.0.26100.33650", "versionType": "custom"}], "platforms": ["x64-based Systems"]}], "datePublic": "2026-10-13T14:00:00.000Z", "references": [{"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88099", "name": "Windows Failover Cluster Denial of Service Vulnerability", "tags": ["vendor-advisory", "patch"]}], "descriptions": [{"lang": "en-US", "value": "Uncaught exception in Windows Failover Cluster allows an unauthorized attacker to deny service over a network."}], "problemTypes": [{"descriptions": [{"lang": "en-US", "type": "CWE", "cweId": "CWE-248", "description": "CWE-248: Uncaught Exception"}]}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "10.0.17763.9376", "versionStartIncluding": "10.0.17763.0"}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "10.0.17763.9376", "versionStartIncluding": "10.0.17763.0"}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "10.0.20348.5761", "versionStartIncluding": "10.0.20348.0"}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "10.0.26100.33650", "versionStartIncluding": "10.0.26100.0"}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "10.0.26100.33650", "versionStartIncluding": "10.0.26100.0"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "shortName": "microsoft", "dateUpdated": "2026-10-16T21:16:55.418Z"}}}, "cveMetadata": {"cveId": "CVE-2026-88099", "state": "PUBLISHED", "dateUpdated": "2026-10-16T21:16:55.418Z", "dateReserved": "2026-09-09T21:51:51.953Z", "assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "datePublished": "2026-10-13T19:00:20.593Z", "assignerShortName": "microsoft"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"platforms": ["x64-based Systems"], "product": "Windows Server 2019", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.17763.9376", "status": "affected", "version": "10.0.17763.0", "versionType": "custom"}]}, {"platforms": ["x64-based Systems"], "product": "Windows Server 2019 (Server Core installation)", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.17763.9376", "status": "affected", "version": "10.0.17763.0", "versionType": "custom"}]}, {"platforms": ["x64-based Systems"], "product": "Windows Server 2022", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.20348.5761", "status": "affected", "version": "10.0.20348.0", "versionType": "custom"}]}, {"platforms": ["x64-based Systems"], "product": "Windows Server 2025", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.26100.33650", "status": "affected", "version": "10.0.26100.0", "versionType": "custom"}]}, {"platforms": ["x64-based Systems"], "product": "Windows Server 2025 (Server Core installation)", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.26100.33650", "status": "affected", "version": "10.0.26100.0", "versionType": "custom"}]}], "source": "secure@microsoft.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:x64:*", "matchCriteriaId": "D8CE3341-8771-4A25-9BF6-2A280D9C536C", "versionEndExcluding": "10.0.17763.9376", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:x64:*", "matchCriteriaId": "A98E694F-9390-488A-A7FB-3E7BF7E988F8", "versionEndExcluding": "10.0.20348.5761", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:*", "matchCriteriaId": "D95E80FE-F34C-4805-9A66-75D090E65BBB", "versionEndExcluding": "10.0.26100.33650", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Uncaught exception in Windows Failover Cluster allows an unauthorized attacker to deny service over a network."}], "id": "CVE-2026-88099", "lastModified": "2026-10-16T15:43:48.160", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 5.9, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 3.6, "source": "secure@microsoft.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-88099", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-10-13T19:58:10.343167Z", "version": "2.0.3"}}]}, "published": "2026-10-13T19:21:27.800", "references": [{"source": "secure@microsoft.com", "tags": ["Patch", "Vendor Advisory"], "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88099"}], "sourceIdentifier": "secure@microsoft.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-248"}], "source": "secure@microsoft.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": ["x64-based_systems"], "status": "affected", "versions": {"scheme": "generic", "value": "[10.0.17763.0,10.0.17763.9376)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Windows Server 2019", "source": "cna", "vendor": "Microsoft"}, "product": "windows_server_2019", "vendor": "microsoft"}, {"configurations": [{"platform": ["x64-based_systems"], "status": "affected", "versions": {"scheme": "generic", "value": "[10.0.17763.0,10.0.17763.9376)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Windows Server 2019 (Server Core installation)", "source": "cna", "vendor": "Microsoft"}, "product": "windows_server_2019_(server_core_installation)", "vendor": "microsoft"}, {"configurations": [{"platform": ["x64-based_systems"], "status": "affected", "versions": {"scheme": "generic", "value": "[10.0.20348.0,10.0.20348.5761)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Windows Server 2022", "source": "cna", "vendor": "Microsoft"}, "product": "windows_server_2022", "vendor": "microsoft"}, {"configurations": [{"platform": ["x64-based_systems"], "status": "affected", "versions": {"scheme": "generic", "value": "[10.0.26100.0,10.0.26100.33650)"}}], "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": "[10.0.26100.0,10.0.26100.33650)"}}], "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": "2026-10-15T19:45:13.332095+00:00", "updated": "2026-10-16T23:15:14.277961+00:00", "vendors": ["microsoft", "microsoft$PRODUCT$windows_server_2019", "microsoft$PRODUCT$windows_server_2019_(server_core_installation)", "microsoft$PRODUCT$windows_server_2022", "microsoft$PRODUCT$windows_server_2025", "microsoft$PRODUCT$windows_server_2025_(server_core_installation)"]}