Connect your agent
AdvisoriesCriticalCheck your lockfilePluginHow it worksPricing Connect your agent

CVE record · CVE-2026-70307

Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability

CVSS 7.0 HighEPSS 0.0026 · 18th percentile

Published by the CVE Program (CNA: microsoft) at 11 Aug 2026, 17:05 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
VendorProductVersions
Microsoft Windows 10 Version 1607
  • affected 10.0.14393.0 to before 10.0.14393.9418 custom
Microsoft Windows 10 Version 1809
  • affected 10.0.17763.0 to before 10.0.17763.9121 custom
Microsoft Windows 10 Version 21H2
  • affected 10.0.19044.0 to before 10.0.19044.7663 custom
Microsoft Windows 10 Version 22H2
  • affected 10.0.19045.0 to before 10.0.19045.7663 custom
Microsoft Windows 11 version 23H2
  • affected 10.0.22631.0 to before 10.0.22631.7517 custom
Microsoft Windows 11 Version 23H2
  • affected 10.0.22631.0 to before 10.0.22631.7517 custom
Microsoft Windows 11 Version 24H2
  • affected 10.0.26100.0 to before 10.0.26100.9168 custom
Microsoft Windows 11 Version 25H2
  • affected 10.0.26200.0 to before 10.0.26200.9168 custom
Microsoft Windows 11 version 26H1
  • affected 10.0.28000.0 to before 10.0.28000.2704 custom
Microsoft Windows Server 2012
  • affected 6.2.9200.0 to before 6.2.9200.26280 custom
Microsoft Windows Server 2012 (Server Core installation)
  • affected 6.2.9200.0 to before 6.2.9200.26280 custom
Microsoft Windows Server 2012 R2
  • affected 6.3.9600.0 to before 6.3.9600.23338 custom
Microsoft Windows Server 2012 R2 (Server Core installation)
  • affected 6.3.9600.0 to before 6.3.9600.23338 custom
Microsoft Windows Server 2016
  • affected 10.0.14393.0 to before 10.0.14393.9418 custom
Microsoft Windows Server 2016 (Server Core installation)
  • affected 10.0.14393.0 to before 10.0.14393.9418 custom
Microsoft Windows Server 2019
  • affected 10.0.17763.0 to before 10.0.17763.9121 custom
Microsoft Windows Server 2019 (Server Core installation)
  • affected 10.0.17763.0 to before 10.0.17763.9121 custom
Microsoft Windows Server 2022
  • affected 10.0.20348.0 to before 10.0.20348.5499 custom
Microsoft Windows Server 2025
  • affected 10.0.26100.0 to before 10.0.26100.33296 custom
Microsoft Windows Server 2025 (Server Core installation)
  • affected 10.0.26100.0 to before 10.0.26100.33296 custom
Identifiers
CVE-2026-70307
CNA
microsoft
Weakness (CWE)
CWE-416
Tags
Published
11 Aug 2026
Updated
10 Nov 2026

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Windows Ancillary Function Driver for WinSock in Windows 10, Windows 11 and Windows Server 2012 builds before the fixed versions listed for each release contains a use-after-free flaw. An authorized local attacker can exploit it to elevate privileges. Upgrade to the fixed build for your Windows version, as no workaround is listed.

Written 12 Nov 2026.

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

ScoreRatingCVSSVectorSource
7.0 High 3.1 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 CNA (microsoft)
  • CISA KEV Not listed.
  • EPSS 0.0026, the 18th percentile, on 12 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

  1. 11 Aug 2026, 17:05 UTC Confirmed by the CVE List

Sources

References from the CNA

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.