{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-21236", "assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "state": "PUBLISHED", "assignerShortName": "microsoft", "dateReserved": "2025-12-11T21:02:05.734Z", "datePublished": "2026-02-10T17:51:23.374Z", "dateUpdated": "2026-02-12T16:25:46.475Z"}, "containers": {"cna": {"title": "Windows Ancillary Function Driver for WinSock 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_10_1809:*:*:*:*:*:*:x86:*", "versionStartIncluding": "10.0.17763.0", "versionEndExcluding": "10.0.17763.8389"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*", "versionStartIncluding": "10.0.17763.0", "versionEndExcluding": "10.0.17763.8389"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*", "versionStartIncluding": "10.0.17763.0", "versionEndExcluding": "10.0.17763.8389"}, {"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:*:*:*:*:*:*:x86:*", "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"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*", "versionStartIncluding": "10.0.14393.0", "versionEndExcluding": "10.0.14393.8868"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*", "versionStartIncluding": "10.0.14393.0", "versionEndExcluding": "10.0.14393.8868"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*", "versionStartIncluding": "10.0.14393.0", "versionEndExcluding": "10.0.14393.8868"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2012:*:*:*:*:*:*:x64:*", "versionStartIncluding": "6.2.9200.0", "versionEndExcluding": "6.2.9200.25923"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2012:*:*:*:*:*:*:x64:*", "versionStartIncluding": "6.2.9200.0", "versionEndExcluding": "6.2.9200.25923"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2012_R2:*:*:*:*:*:*:x64:*", "versionStartIncluding": "6.3.9600.0", "versionEndExcluding": "6.3.9600.23022"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2012_R2:*:*:*:*:*:*:x64:*", "versionStartIncluding": "6.3.9600.0", "versionEndExcluding": "6.3.9600.23022"}]}]}], "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 10 Version 1809", "platforms": ["32-bit Systems", "x64-based Systems"], "versions": [{"version": "10.0.17763.0", "lessThan": "10.0.17763.8389", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2019", "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.17763.0", "lessThan": "10.0.17763.8389", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2019 (Server Core installation)", "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.17763.0", "lessThan": "10.0.17763.8389", "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": ["32-bit Systems", "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", "32-bit 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"}]}, {"vendor": "Microsoft", "product": "Windows 10 Version 1607", "platforms": ["32-bit Systems", "x64-based Systems"], "versions": [{"version": "10.0.14393.0", "lessThan": "10.0.14393.8868", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2016", "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.14393.0", "lessThan": "10.0.14393.8868", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2016 (Server Core installation)", "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.14393.0", "lessThan": "10.0.14393.8868", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2012", "platforms": ["x64-based Systems"], "versions": [{"version": "6.2.9200.0", "lessThan": "6.2.9200.25923", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2012 (Server Core installation)", "platforms": ["x64-based Systems"], "versions": [{"version": "6.2.9200.0", "lessThan": "6.2.9200.25923", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2012 R2", "platforms": ["x64-based Systems"], "versions": [{"version": "6.3.9600.0", "lessThan": "6.3.9600.23022", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2012 R2 (Server Core installation)", "platforms": ["x64-based Systems"], "versions": [{"version": "6.3.9600.0", "lessThan": "6.3.9600.23022", "versionType": "custom", "status": "affected"}]}], "descriptions": [{"value": "Heap-based buffer overflow in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.", "lang": "en-US"}], "problemTypes": [{"descriptions": [{"description": "CWE-122: Heap-based Buffer Overflow", "lang": "en-US", "type": "CWE", "cweId": "CWE-122"}]}], "providerMetadata": {"orgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "shortName": "microsoft", "dateUpdated": "2026-02-12T16:25:46.475Z"}, "references": [{"name": "Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability", "tags": ["vendor-advisory", "patch"], "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21236"}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en-US", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "baseSeverity": "HIGH", "baseScore": 7.8, "vectorString": "CVSS:3.1/AV:L/AC:L/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-2026-21236"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-02-11T04:55:47.588Z"}}]}}

{}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*", "matchCriteriaId": "E78A20FD-B910-43DF-BE89-E971E2FD0049", "versionEndExcluding": "10.0.14393.8868", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*", "matchCriteriaId": "B941280B-97F6-4F60-80A3-40482A74488D", "versionEndExcluding": "10.0.14393.8868", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*", "matchCriteriaId": "C09C54DA-6AB0-4696-A2F2-C11CFC292EA9", "versionEndExcluding": "10.0.17763.8389", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*", "matchCriteriaId": "369B4E41-3895-4CB7-BD37-D2E4A4D52FB9", "versionEndExcluding": "10.0.17763.8389", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:arm64:*", "matchCriteriaId": "EDB3FD9A-2786-4EC1-8989-2B0D054E0307", "versionEndExcluding": "10.0.19044.6937", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x64:*", "matchCriteriaId": "893DBA65-116B-4AE0-80E1-50458CB5FDAD", "versionEndExcluding": "10.0.19044.6937", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x86:*", "matchCriteriaId": "37E2BFF1-28C0-4FA0-9A6C-020146E4AD54", "versionEndExcluding": "10.0.19044.6937", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:arm64:*", "matchCriteriaId": "3ABF7E9C-769A-4330-AD97-FE3CD766E577", "versionEndExcluding": "10.0.19045.6937", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x64:*", "matchCriteriaId": "F54B0C64-9A1F-470B-9824-322CF362507F", "versionEndExcluding": "10.0.19045.6937", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x86:*", "matchCriteriaId": "A5BD3F0C-1E6F-4937-806C-B87CA19C2830", "versionEndExcluding": "10.0.19045.6937", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:*", "matchCriteriaId": "B273EF5A-3157-4842-AE91-CEC289813902", "versionEndExcluding": "10.0.22631.6649", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:*", "matchCriteriaId": "CD2513FC-D399-4DBF-921F-13B4D1497127", "versionEndExcluding": "10.0.22631.6649", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:*", "matchCriteriaId": "B08450A0-0F7E-4A05-8989-900221992766", "versionEndExcluding": "10.0.26100.7781", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:*", "matchCriteriaId": "9D30B348-DAE7-43EC-85FA-38E1715258A9", "versionEndExcluding": "10.0.26100.7781", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:*", "matchCriteriaId": "8F23FFCF-9C69-4D27-AF21-D09A6041AA3A", "versionEndExcluding": "10.0.26200.7781", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:*", "matchCriteriaId": "D1D93202-BDDB-438F-934E-1FE904B3651B", "versionEndExcluding": "10.0.26200.7781", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*", "matchCriteriaId": "A7DF96F8-BA6A-4780-9CA3-F719B3F81074", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*", "matchCriteriaId": "DB18C4CE-5917-401E-ACF7-2747084FD36E", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*", "matchCriteriaId": "E21BC97D-1C11-41FD-9A20-34A2BC535BD9", "versionEndExcluding": "10.0.14393.8868", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*", "matchCriteriaId": "B6E3E93E-8160-4BFB-B5CB-85740922CF7E", "versionEndExcluding": "10.0.17763.8389", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*", "matchCriteriaId": "9E19FC4B-C3CC-4924-9A0B-5E4F100280D4", "versionEndExcluding": "10.0.20348.4711", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:*:*", "matchCriteriaId": "F0EA3C51-C3FE-494A-92D9-D3B1C301CB54", "versionEndExcluding": "10.0.25398.2149", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*", "matchCriteriaId": "33AF95F4-504F-40EF-9F64-5D6F7B40114F", "versionEndExcluding": "10.0.26100.32313", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Heap-based buffer overflow in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally."}], "id": "CVE-2026-21236", "lastModified": "2026-02-11T21:07:23.287", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "secure@microsoft.com", "type": "Primary"}]}, "published": "2026-02-10T18:16:24.250", "references": [{"source": "secure@microsoft.com", "tags": ["Vendor Advisory"], "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21236"}], "sourceIdentifier": "secure@microsoft.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-122"}], "source": "secure@microsoft.com", "type": "Primary"}, {"description": [{"lang": "en", "value": "CWE-787"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{}