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major vulnerability· requires attention

Core Windows networking driver vulnerability affecting broad Windows deployments; local exploit can yield SYSTEM privileges. Listed in CISA KEV and high CVSS, so wide organizational impact.

Systems

CVE-2026-68820

9.8
Critical
KEV · Exploited in wildEPSS 6%Patch availableAug 18, 2026

Local privilege escalation in Windows Ancillary Function Driver for WinSock (use-after-free).

common questions

Is CVE-2026-68820 being exploited?

Yes. CVE-2026-68820 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.

How severe is CVE-2026-68820?

CVE-2026-68820 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.

Is there a patch for CVE-2026-68820?

Yes. A fix has been recorded for CVE-2026-68820. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.

What does CVE-2026-68820 affect?

CVE-2026-68820 affects Microsoft Windows Ancillary Function Driver for WinSock, Windows client and server versions (per vendor advisory). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.

What should I do about CVE-2026-68820?

Apply Microsoft's security update or vendor mitigations immediately and follow CISA BOD 26-04.

Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.

executive summary
technical analysis
affected
Microsoft Windows Ancillary Function Driver for WinSockWindows client and server versions (per vendor advisory)
impact

Authorized local attacker can exploit a use-after-free to escalate to SYSTEM, enabling code execution, persistence, and credential access.

action required

Immediate action required

affected versions
Microsoft Windows 10 Version 1607
  • affected>= 10.0.14393.0 and < 10.0.14393.9418
Microsoft Windows 10 Version 1809
  • affected>= 10.0.17763.0 and < 10.0.17763.9121
Microsoft Windows 10 Version 21H2
  • affected>= 10.0.19044.0 and < 10.0.19044.7663
Microsoft Windows 10 Version 22H2
  • affected>= 10.0.19045.0 and < 10.0.19045.7663
Microsoft Windows 11 version 23H2
  • affected>= 10.0.22631.0 and < 10.0.22631.7517
Microsoft Windows 11 Version 23H2
  • affected>= 10.0.22631.0 and < 10.0.22631.7517
Microsoft Windows 11 Version 24H2
  • affected>= 10.0.26100.0 and < 10.0.26100.9168
Microsoft Windows 11 Version 25H2
  • affected>= 10.0.26200.0 and < 10.0.26200.9168
Microsoft Windows 11 version 26H1
  • affected>= 10.0.28000.0 and < 10.0.28000.2704
Microsoft Windows Server 2012
  • affected>= 6.2.9200.0 and < 6.2.9200.26280
Microsoft Windows Server 2012 R2
  • affected>= 6.3.9600.0 and < 6.3.9600.23338
Microsoft Windows Server 2012 R2 (Server Core installation)
  • affected>= 6.3.9600.0 and < 6.3.9600.23338
Microsoft Windows Server 2012 (Server Core installation)
  • affected>= 6.2.9200.0 and < 6.2.9200.26280
Microsoft Windows Server 2016
  • affected>= 10.0.14393.0 and < 10.0.14393.9418
Microsoft Windows Server 2016 (Server Core installation)
  • affected>= 10.0.14393.0 and < 10.0.14393.9418
Microsoft Windows Server 2019
  • affected>= 10.0.17763.0 and < 10.0.17763.9121
Microsoft Windows Server 2019 (Server Core installation)
  • affected>= 10.0.17763.0 and < 10.0.17763.9121
Microsoft Windows Server 2022
  • affected>= 10.0.20348.0 and < 10.0.20348.5499
Microsoft Windows Server 2025
  • affected>= 10.0.26100.0 and < 10.0.26100.33296
Microsoft Windows Server 2025 (Server Core installation)
  • affected>= 10.0.26100.0 and < 10.0.26100.33296

As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.

how to fix
Remediation steps are tailored for users whose stack is affected. Add this technology to your stack to see the fix checklist.
references
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