CVE-2026-77889

{"id": "CVE-2026-77889", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-77889", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-09-08T18:56:02.498196Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "secure@microsoft.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}]}, "affected": [{"source": "secure@microsoft.com", "affectedData": [{"vendor": "Microsoft", "product": "Windows 10 Version 1607", "versions": [{"status": "affected", "version": "10.0.14393.0", "lessThan": "10.0.14393.9512", "versionType": "custom"}], "platforms": ["32-bit Systems", "x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows 10 Version 1809", "versions": [{"status": "affected", "version": "10.0.17763.0", "lessThan": "10.0.17763.9245", "versionType": "custom"}], "platforms": ["32-bit Systems", "x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2012", "versions": [{"status": "affected", "version": "6.2.9200.0", "lessThan": "6.2.9200.26349", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2012 (Server Core installation)", "versions": [{"status": "affected", "version": "6.2.9200.0", "lessThan": "6.2.9200.26349", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2012 R2", "versions": [{"status": "affected", "version": "6.3.9600.0", "lessThan": "6.3.9600.23397", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2012 R2 (Server Core installation)", "versions": [{"status": "affected", "version": "6.3.9600.0", "lessThan": "6.3.9600.23397", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2016", "versions": [{"status": "affected", "version": "10.0.14393.0", "lessThan": "10.0.14393.9512", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2016 (Server Core installation)", "versions": [{"status": "affected", "version": "10.0.14393.0", "lessThan": "10.0.14393.9512", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2019", "versions": [{"status": "affected", "version": "10.0.17763.0", "lessThan": "10.0.17763.9245", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2019 (Server Core installation)", "versions": [{"status": "affected", "version": "10.0.17763.0", "lessThan": "10.0.17763.9245", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2022", "versions": [{"status": "affected", "version": "10.0.20348.0", "lessThan": "10.0.20348.5622", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2025", "versions": [{"status": "affected", "version": "10.0.26100.0", "lessThan": "10.0.26100.33438", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2025 (Server Core installation)", "versions": [{"status": "affected", "version": "10.0.26100.0", "lessThan": "10.0.26100.33438", "versionType": "custom"}], "platforms": ["x64-based Systems"]}]}], "published": "2026-09-08T18:20:38.587", "references": [{"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-77889", "tags": ["Patch", "Vendor Advisory"], "source": "secure@microsoft.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "secure@microsoft.com", "description": [{"lang": "en", "value": "CWE-843"}]}], "descriptions": [{"lang": "en", "value": "Access of resource using incompatible type ('type confusion') in Windows DHCP Server allows an unauthorized attacker to deny service over a network."}], "lastModified": "2026-09-16T15:09:27.697", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*", "vulnerable": true, "matchCriteriaId": "F5BC051B-C14F-43DF-B3A2-A32EE0DDC142", "versionEndExcluding": "10.0.14393.9512"}, {"criteria": "cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*", "vulnerable": true, "matchCriteriaId": "D8DA8FA6-35F6-4E0F-A9C0-37CB88186C5B", "versionEndExcluding": "10.0.14393.9512"}, {"criteria": "cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*", "vulnerable": true, "matchCriteriaId": "81786843-7838-4C74-AEA6-E64B6B354387", "versionEndExcluding": "10.0.17763.9245"}, {"criteria": "cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*", "vulnerable": true, "matchCriteriaId": "D5E29D31-09E1-4C19-AAB0-191AA960C778", "versionEndExcluding": "10.0.17763.9245"}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "A7DF96F8-BA6A-4780-9CA3-F719B3F81074"}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "DB18C4CE-5917-401E-ACF7-2747084FD36E"}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C7CF508B-369A-4854-97BF-EE90E0A5BF7B", "versionEndExcluding": "10.0.14393.9512"}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "14138B1B-9554-4B1D-84C6-485FB9763DA4", "versionEndExcluding": "10.0.17763.9245"}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "496A12F9-40BF-4A40-948B-BDB1C5D17DCB", "versionEndExcluding": "10.0.20348.5622"}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "48D75543-6B91-41E9-A1FB-1A09A2CBD738", "versionEndExcluding": "10.0.26100.33438"}], "operator": "OR"}]}], "sourceIdentifier": "secure@microsoft.com"}