{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-21242", "assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "state": "PUBLISHED", "assignerShortName": "microsoft", "dateReserved": "2025-12-11T21:02:05.735Z", "datePublished": "2026-02-10T17:51:21.565Z", "dateUpdated": "2026-02-11T04:55:37.426Z"}, "containers": {"cna": {"title": "Windows Subsystem for Linux Elevation of Privilege Vulnerability", "datePublic": "2026-02-10T08:00:00.000Z", "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_26H1:*:*:*:*:*:*:arm64:*", "versionStartIncluding": "10.0.28000.0", "versionEndExcluding": "10.0.28000.1575"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_26H1:*:*:*:*:*:*:x64:*", "versionStartIncluding": "10.0.28000.0", "versionEndExcluding": "10.0.28000.1575"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*", "versionStartIncluding": "10.0.20348.0", "versionEndExcluding": "10.0.20348.4773"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_21H2:*:*:*:*:*:*:arm64:*", "versionStartIncluding": "10.0.19044.0", "versionEndExcluding": "10.0.19044.6937"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_22H2:*:*:*:*:*:*:x64:*", "versionStartIncluding": "10.0.19045.0", "versionEndExcluding": "10.0.19045.6937"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*", "versionStartIncluding": "10.0.26100.0", "versionEndExcluding": "10.0.26100.32370"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_25H2:*:*:*:*:*:*:arm64:*", "versionStartIncluding": "10.0.26200.0", "versionEndExcluding": "10.0.26200.7840"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_23H2:*:*:*:*:*:*:arm64:*", "versionStartIncluding": "10.0.22631.0", "versionEndExcluding": "10.0.22631.6649"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_23H2:*:*:*:*:*:*:x64:*", "versionStartIncluding": "10.0.22631.0", "versionEndExcluding": "10.0.22631.6649"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_23h2:*:*:*:*:*:*:*:*", "versionStartIncluding": "10.0.25398.0", "versionEndExcluding": "10.0.25398.2149"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_24H2:*:*:*:*:*:*:arm64:*", "versionStartIncluding": "10.0.26100.0", "versionEndExcluding": "10.0.26100.7840"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*", "versionStartIncluding": "10.0.26100.0", "versionEndExcluding": "10.0.26100.32370"}]}]}], "affected": [{"vendor": "Microsoft", "product": "Windows 11 version 26H1", "platforms": ["ARM64-based Systems"], "versions": [{"version": "10.0.28000.0", "lessThan": "10.0.28000.1575", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows 11 Version 26H1", "versions": [{"version": "10.0.28000.0", "lessThan": "10.0.28000.1575", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2022", "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.20348.0", "lessThan": "10.0.20348.4773", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows 10 Version 21H2", "platforms": ["ARM64-based Systems", "x64-based Systems"], "versions": [{"version": "10.0.19044.0", "lessThan": "10.0.19044.6937", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows 10 Version 22H2", "platforms": ["x64-based Systems", "ARM64-based Systems"], "versions": [{"version": "10.0.19045.0", "lessThan": "10.0.19045.6937", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2025 (Server Core installation)", "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.26100.0", "lessThan": "10.0.26100.32370", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows 11 Version 25H2", "versions": [{"version": "10.0.26200.0", "lessThan": "10.0.26200.7840", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows 11 version 22H3", "platforms": ["ARM64-based Systems"], "versions": [{"version": "10.0.22631.0", "lessThan": "10.0.22631.6649", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows 11 Version 23H2", "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.22631.0", "lessThan": "10.0.22631.6649", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2022, 23H2 Edition (Server Core installation)", "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.25398.0", "lessThan": "10.0.25398.2149", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows 11 Version 24H2", "platforms": ["ARM64-based Systems", "x64-based Systems"], "versions": [{"version": "10.0.26100.0", "lessThan": "10.0.26100.7840", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2025", "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.26100.0", "lessThan": "10.0.26100.32370", "versionType": "custom", "status": "affected"}]}], "descriptions": [{"value": "Use after free in Windows Subsystem for Linux allows an authorized attacker to elevate privileges locally.", "lang": "en-US"}], "problemTypes": [{"descriptions": [{"description": "CWE-416: Use After Free", "lang": "en-US", "type": "CWE", "cweId": "CWE-416"}]}], "providerMetadata": {"orgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "shortName": "microsoft", "dateUpdated": "2026-02-11T01:14:46.875Z"}, "references": [{"name": "Windows Subsystem for Linux Elevation of Privilege Vulnerability", "tags": ["vendor-advisory", "patch"], "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21242"}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en-US", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "baseSeverity": "HIGH", "baseScore": 7, "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C"}}]}, "adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-02-05T00:00:00+00:00", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3", "id": "CVE-2026-21242"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-02-11T04:55:37.426Z"}}]}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "Use after free in Windows Subsystem for Linux allows an authorized attacker to elevate privileges locally."}], "id": "CVE-2026-21242", "lastModified": "2026-02-10T21:51:48.077", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.0, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.0, "impactScore": 5.9, "source": "secure@microsoft.com", "type": "Primary"}]}, "published": "2026-02-10T18:16:25.323", "references": [{"source": "secure@microsoft.com", "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21242"}], "sourceIdentifier": "secure@microsoft.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "secure@microsoft.com", "type": "Primary"}]}

{}

{}