FKIE_CVE-2026-42911
Vulnerability from fkie_nvd - Published: 2026-06-09 17:17 - Updated: 2026-06-17 10:48
Severity
Summary
Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
References
| URL | Tags | ||
|---|---|---|---|
| secure@microsoft.com | https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42911 | Vendor Advisory |
Impacted products
{
"affected": [
{
"affectedData": [
{
"platforms": [
"32-bit Systems",
"x64-based Systems"
],
"product": "Windows 10 Version 1607",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.14393.9234",
"status": "affected",
"version": "10.0.14393.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"32-bit Systems",
"x64-based Systems"
],
"product": "Windows 10 Version 1809",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.17763.8880",
"status": "affected",
"version": "10.0.17763.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"32-bit Systems",
"ARM64-based Systems",
"x64-based Systems"
],
"product": "Windows 10 Version 21H2",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.19044.7417",
"status": "affected",
"version": "10.0.19044.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"32-bit Systems",
"ARM64-based Systems",
"x64-based Systems"
],
"product": "Windows 10 Version 22H2",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.19045.7417",
"status": "affected",
"version": "10.0.19045.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"ARM64-based Systems"
],
"product": "Windows 11 version 23H2",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.22631.7219",
"status": "affected",
"version": "10.0.22631.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"x64-based Systems"
],
"product": "Windows 11 Version 23H2",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.22631.7219",
"status": "affected",
"version": "10.0.22631.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"ARM64-based Systems",
"x64-based Systems"
],
"product": "Windows 11 Version 24H2",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.26100.8655",
"status": "affected",
"version": "10.0.26100.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"ARM64-based Systems",
"x64-based Systems"
],
"product": "Windows 11 Version 25H2",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.26200.8655",
"status": "affected",
"version": "10.0.26200.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"ARM64-based Systems",
"x64-based Systems"
],
"product": "Windows 11 version 26H1",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.28000.2269",
"status": "affected",
"version": "10.0.28000.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"x64-based Systems"
],
"product": "Windows Server 2012",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "6.2.9200.26132",
"status": "affected",
"version": "6.2.9200.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"x64-based Systems"
],
"product": "Windows Server 2012 (Server Core installation)",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "6.2.9200.26132",
"status": "affected",
"version": "6.2.9200.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"x64-based Systems"
],
"product": "Windows Server 2012 R2",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "6.3.9600.23228",
"status": "affected",
"version": "6.3.9600.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"x64-based Systems"
],
"product": "Windows Server 2012 R2 (Server Core installation)",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "6.3.9600.23228",
"status": "affected",
"version": "6.3.9600.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"x64-based Systems"
],
"product": "Windows Server 2016",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.14393.9234",
"status": "affected",
"version": "10.0.14393.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"x64-based Systems"
],
"product": "Windows Server 2016 (Server Core installation)",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.14393.9234",
"status": "affected",
"version": "10.0.14393.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"x64-based Systems"
],
"product": "Windows Server 2019",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.17763.8880",
"status": "affected",
"version": "10.0.17763.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"x64-based Systems"
],
"product": "Windows Server 2019 (Server Core installation)",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.17763.8880",
"status": "affected",
"version": "10.0.17763.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"x64-based Systems"
],
"product": "Windows Server 2022",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.20348.5256",
"status": "affected",
"version": "10.0.20348.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"x64-based Systems"
],
"product": "Windows Server 2025",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.26100.32995",
"status": "affected",
"version": "10.0.26100.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"x64-based Systems"
],
"product": "Windows Server 2025 (Server Core installation)",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.26100.32995",
"status": "affected",
"version": "10.0.26100.0",
"versionType": "custom"
}
]
}
],
"source": "secure@microsoft.com"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*",
"matchCriteriaId": "039BC4EF-6E49-4A8C-B1A4-BFAD9F24EC01",
"versionEndExcluding": "10.0.14393.9234",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*",
"matchCriteriaId": "2221A0A5-45F3-4903-943A-19E7AA69496B",
"versionEndExcluding": "10.0.14393.9234",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*",
"matchCriteriaId": "03A4C97D-FE89-4367-9A0E-E4E65BD49E18",
"versionEndExcluding": "10.0.17763.8880",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*",
"matchCriteriaId": "FE809AA0-E917-495F-BB11-59215F47E14F",
"versionEndExcluding": "10.0.17763.8880",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:arm64:*",
"matchCriteriaId": "3E87DD4E-44FC-4B9A-99AB-D1DB3C67EF79",
"versionEndExcluding": "10.0.19044.7417",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x64:*",
"matchCriteriaId": "A21A9BC4-DE4F-46BE-944F-AD6CAA92BF32",
"versionEndExcluding": "10.0.19044.7417",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x86:*",
"matchCriteriaId": "911336E9-FAEA-4EB5-96D7-8049AE622C61",
"versionEndExcluding": "10.0.19044.7417",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:arm64:*",
"matchCriteriaId": "B8BB8399-35C5-4654-A679-5E105773615B",
"versionEndExcluding": "10.0.19045.7417",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x64:*",
"matchCriteriaId": "55571EDC-8323-4BAE-B363-113ACEF55CB2",
"versionEndExcluding": "10.0.19045.7417",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x86:*",
"matchCriteriaId": "D14AC77E-34F3-4704-A068-D9020FF60A8C",
"versionEndExcluding": "10.0.19045.7417",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:*",
"matchCriteriaId": "92508776-88BE-4872-99DB-1F690F71ADEF",
"versionEndExcluding": "10.0.22631.7219",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:*",
"matchCriteriaId": "410079AC-180E-4D7F-B7F6-784E36FEA036",
"versionEndExcluding": "10.0.22631.7219",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:*",
"matchCriteriaId": "32DB4863-6880-40B4-8EC1-9E0F40E81D7F",
"versionEndExcluding": "10.0.26100.8655",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:*",
"matchCriteriaId": "E691C9E5-5271-436D-A7FD-C25BEA4D447D",
"versionEndExcluding": "10.0.26100.8655",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:*",
"matchCriteriaId": "1D3DEE4A-9959-4716-BC39-35660AC22BC4",
"versionEndExcluding": "10.0.26200.8655",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:*",
"matchCriteriaId": "1000C085-A5D7-4027-B9C1-6AE7DA468FB7",
"versionEndExcluding": "10.0.26200.8655",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:arm64:*",
"matchCriteriaId": "9C7AD7ED-307B-40B9-B706-45FB178C36D8",
"versionEndExcluding": "10.0.28000.2269",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:x64:*",
"matchCriteriaId": "8967AF79-CAD0-4F87-85A5-95D031C9FEFA",
"versionEndExcluding": "10.0.28000.2269",
"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": "B3F7E1F6-48D5-4ECB-9BF8-4238903FC194",
"versionEndExcluding": "10.0.14393.9234",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*",
"matchCriteriaId": "07C08212-A30E-4434-A17C-542E45D1E272",
"versionEndExcluding": "10.0.17763.8880",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*",
"matchCriteriaId": "27363D97-D4A9-4709-9854-F78F7EBCFB27",
"versionEndExcluding": "10.0.20348.5256",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:*",
"matchCriteriaId": "E127A6E6-C261-4039-8A13-A2FAC4606573",
"versionEndExcluding": "10.0.26100.32995",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally."
}
],
"id": "CVE-2026-42911",
"lastModified": "2026-06-17T10:48:36.713",
"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": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-42911",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-06-05T00:00:00+00:00",
"version": "2.0.3"
}
}
]
},
"published": "2026-06-09T17:17:11.090",
"references": [
{
"source": "secure@microsoft.com",
"tags": [
"Vendor Advisory"
],
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42911"
}
],
"sourceIdentifier": "secure@microsoft.com",
"vulnStatus": "Analyzed",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-416"
}
],
"source": "secure@microsoft.com",
"type": "Secondary"
}
]
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
Loading…