CVE-2026-70237: 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.
- Upgrade
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Fixed in 6.3.9600.23470Patch KB5126836 - Upgrade
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Fixed in 10.0.28000.3231Patch KB5127646 - Upgrade
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Fixed in 10.0.14393.9612Patch KB5126868 - Upgrade
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Fixed in 10.0.26300.9711Patch KB5127648 - Upgrade
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Fixed in 6.2.9200.26434Patch KB5126835 - Upgrade
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Fixed in 10.0.26100.9711Patch KB5127648 - Upgrade
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Fixed in 10.0.19044.7807Patch KB5126657 - Upgrade
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Fixed in 10.0.17763.9376Patch KB5126651 - Upgrade
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Fixed in 10.0.26100.33650Patch KB5126646 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26200.9711Patch KB5127648 - Upgrade
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Fixed in 10.0.20348.5761Patch KB5126655 - Upgrade
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Fixed in 10.0.22631.7652Patch KB5126653
Event History
Frequently Asked Questions
Who is exposed to this vulnerability?
Systems running the listed Microsoft Windows client or server products are in scope. Exploitation is local, so exposure depends on whether an attacker can run code as an authorized low-privileged user on the system.
What access does an attacker need to exploit it?
The attacker must already have local access and authorization on the affected machine, with low privileges. No user interaction is required, but the attack complexity is rated high.
What is the likely impact if exploitation succeeds?
A successful exploit can elevate the attacker’s privileges locally. The supplied vector indicates high impact to confidentiality, integrity, and availability.