Is CVE-2026-34344 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-34344 being exploited in the wild.

How severe is CVE-2026-34344?

High severity, with a CVSS score of 7.8, published 12 May 2026.

Is there a fix for CVE-2026-34344?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-34344 attacked?

It is attacked with local access, in an operating system.

Am I affected by CVE-2026-34344?

Check whether you run Microsoft Windows Ancillary Function Driver for WinSock. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-34344: Microsoft Windows type confusion in Ancillary Function Driver for WinSock

CVE-2026-34344 · Severity: high · CVSS 7.8 · Published 2026-05-12

A security vulnerability exists in a core Windows networking component responsible for managing socket connections. An attacker who already has basic access to a computer could exploit this flaw to gain full administrative or system-level control. This could allow them to bypass security restrictions, access sensitive data, or install malicious software across the entire operating system.

Technologies: Microsoft Windows Ancillary Function Driver for WinSock. Vendors: Microsoft.

Quick answers

Is CVE-2026-34344 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-34344 being exploited in the wild.
How severe is CVE-2026-34344?: High severity, with a CVSS score of 7.8, published 12 May 2026.
Which products and versions are affected?: Microsoft Windows Ancillary Function Driver for WinSock (afd.sys).
Is there a fix for CVE-2026-34344?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-34344 attacked?: It is attacked with local access, in an operating system.
Am I affected by CVE-2026-34344?: Check whether you run Microsoft Windows Ancillary Function Driver for WinSock. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

This vulnerability is classified as a type confusion (CWE-843) within the Windows Ancillary Function Driver for WinSock (afd.sys). The flaw occurs when the driver improperly handles objects in memory, allowing an attacker to supply a specifically crafted input that causes the driver to access a resource using an incompatible type. To exploit this, an attacker must first have local execution privileges on the target system. Successful exploitation allows the attacker to execute code with elevated privileges, typically SYSTEM, leading to a full compromise of the host's integrity and confidentiality. Microsoft has released security updates to address this issue.

Affected products

Microsoft Windows Ancillary Function Driver for WinSock (afd.sys)

Timeline

2026-05-12: disclosed: Initial disclosure by Microsoft and NVD.
2026-05-12: advisory: Microsoft MSRC advisory published.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-34344

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