CVE-2026-77894

{"id": "CVE-2026-77894", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-77894", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-09-04T00:00:00+00:00"}}], "cvssMetricV31": [{"type": "Secondary", "source": "secure@microsoft.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.0, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 1.0}]}, "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 10 Version 21H2", "versions": [{"status": "affected", "version": "10.0.19044.0", "lessThan": "10.0.19044.7725", "versionType": "custom"}], "platforms": ["32-bit Systems", "ARM64-based Systems", "x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows 10 Version 22H2", "versions": [{"status": "affected", "version": "10.0.19045.0", "lessThan": "10.0.19045.7725", "versionType": "custom"}], "platforms": ["32-bit Systems", "ARM64-based Systems", "x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows 11 version 23H2", "versions": [{"status": "affected", "version": "10.0.22631.0", "lessThan": "10.0.22631.7582", "versionType": "custom"}], "platforms": ["ARM64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows 11 Version 23H2", "versions": [{"status": "affected", "version": "10.0.22631.0", "lessThan": "10.0.22631.7582", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows 11 Version 24H2", "versions": [{"status": "affected", "version": "10.0.26100.0", "lessThan": "10.0.26100.9445", "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": "10.0.26200.9445", "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": "10.0.28000.2954", "versionType": "custom"}], "platforms": ["ARM64-based 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": "6.3.9600.23398", "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": "6.3.9600.23398", "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": "2026-09-08T18:20:39.367", "references": [{"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-77894", "tags": ["Patch", "Vendor Advisory"], "source": "secure@microsoft.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "secure@microsoft.com", "description": [{"lang": "en", "value": "CWE-362"}, {"lang": "en", "value": "CWE-416"}]}], "descriptions": [{"lang": "en", "value": "Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Installer allows an authorized attacker to elevate privileges locally."}], "lastModified": "2026-09-24T23:19:03.510", "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": 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"sourceIdentifier": "secure@microsoft.com"}