CVE-2026-88099 - Vulnerability Details - OpenCVE

Uncaught exception in Windows Failover Cluster allows an unauthorized attacker to deny service over a network.

No CVSS v4.0

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Vendors	Products
Microsoft Subscribe	Windows Server 2019 Subscribe Windows Server 2022 Subscribe Windows Server 2025 Subscribe

No data.

No data.

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References

Link	Providers
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88099

History

Tue, 13 Oct 2026 19:15:00 +0000

Type	Values Removed	Values Added
Description		Uncaught exception in Windows Failover Cluster allows an unauthorized attacker to deny service over a network.
Title		Windows Failover Cluster Denial of Service Vulnerability
First Time appeared		Microsoft Microsoft windows Server 2019 Microsoft windows Server 2022 Microsoft windows Server 2025
Weaknesses		CWE-248
CPEs		cpe:2.3:o:microsoft:windows_server_2019:::::::: cpe:2.3:o:microsoft:windows_server_2022:::::::: cpe:2.3:o:microsoft:windows_server_2025::::::::
Vendors & Products		Microsoft Microsoft windows Server 2019 Microsoft windows Server 2022 Microsoft windows Server 2025
References		https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88099
Metrics		cvssV3_1 `{'score': 5.9, 'vector': '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'}`

Projects

Sign in to view the affected projects.

MITRE

Status: PUBLISHED

Assigner: microsoft

Published: 2026-10-13T19:00:20.593Z

Updated: 2026-10-13T19:16:24.656Z

Reserved: 2026-09-09T21:51:51.953Z

Link: CVE-2026-88099

Vulnrichment

No data.

NVD

Status : Awaiting Analysis

Published: 2026-10-13T19:21:27.800

Modified: 2026-10-13T19:27:28.620

Link: CVE-2026-88099

Redhat

No data.

OpenCVE Enrichment

No data.

Weaknesses

CWE-248

{"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": "2026-10-13T19:16:24.656Z"}, "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": "2026-10-13T19:16:24.656Z"}, "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"}}]}}}

{"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": "[email protected]"}], "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": "2026-10-13T19:27:28.620", "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": "[email protected]", "type": "Primary"}]}, "published": "2026-10-13T19:21:27.800", "references": [{"source": "[email protected]", "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88099"}], "sourceIdentifier": "[email protected]", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-248"}], "source": "[email protected]", "type": "Primary"}]}