CVE-2026-70307: Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
Other sources
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
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Fixed in 6.2.9200.26279Patch KB5120385 - Upgrade
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Fixed in 6.3.9600.23337Patch KB5120386 - Upgrade
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Fixed in 10.0.14393.9418Patch KB5120418 - Upgrade
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Fixed in 10.0.28000.2704Patch KB5121000 - Upgrade
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Fixed in 10.0.26100.33296Fixed in 10.0.26100.33222Patch KB5120228 - Upgrade
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Fixed in 10.0.26100.9168Fixed in 10.0.26000.9106Patch KB5120994 - Upgrade
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Fixed in 10.0.22631.7517Patch KB5120240 - Upgrade
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Fixed in 10.0.26100.9168Fixed in 10.0.26100.9106Patch KB5120994 - Upgrade
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Fixed in 10.0.26200.9168Fixed in 10.0.26100.9106Patch KB5120994 - Upgrade
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Fixed in 10.0.19045.7663Patch KB5120249 - Upgrade
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Fixed in 10.0.19044.7663Patch KB5120249 - Upgrade
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Fixed in 10.0.17763.9115Patch KB5120238 - Upgrade
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Fixed in 10.0.20348.5499Fixed in 10.0.20348.5440Patch KB5120229
Event History
Frequently Asked Questions
What is the severity of CVE-2026-70307?
CVE-2026-70307 has a severity rating of high, with a score of 7.
How does CVE-2026-70307 affect Windows systems?
CVE-2026-70307 allows an authorized attacker to elevate privileges locally on affected Windows systems.
Which Windows versions are impacted by CVE-2026-70307?
CVE-2026-70307 affects Microsoft Windows 10, Windows 11, and multiple versions of Windows Server including 2012, 2016, 2019, 2022, and 2025.
What type of vulnerability is CVE-2026-70307 classified as?
CVE-2026-70307 is classified as a use after free vulnerability.
What is the potential impact of exploiting CVE-2026-70307?
Exploiting CVE-2026-70307 could allow an attacker to gain elevated privileges, potentially compromising system security.