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CVE-2026-34335 Microsoft CVE debrief

CVE-2026-34335 is a HIGH severity vulnerability in Windows Ancillary Function Driver for WinSock. The vulnerability is caused by a use-after-free issue, which allows an authorized attacker to elevate privileges locally. The vulnerability has a CVSS score of 7 and was published on 2026-06-09T17:17:05.117Z.

Vendor
Microsoft
Product
Windows 10 Version 1607
CVSS
HIGH 7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-09
Original CVE updated
2026-06-10
Advisory published
2026-06-09
Advisory updated
2026-06-10

Who should care

Administrators and users of Windows operating systems should be aware of this vulnerability and take necessary actions to mitigate it.

Technical summary

The vulnerability is caused by a use-after-free issue in Windows Ancillary Function Driver for WinSock. This allows an authorized attacker to elevate privileges locally. The vulnerability has been assigned a CVSS score of 7 and a CVSS vector of CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.

Defensive priority

HIGH

Recommended defensive actions

  • Apply patches or updates provided by Microsoft to vulnerable systems.
  • Consider implementing additional security measures, such as access controls and monitoring.

Evidence notes

The vulnerability is described in the CVE record and NVD detail pages.

Official resources

CVE-2026-34335 was published on 2026-06-09T17:17:05.117Z and modified on 2026-06-10T19:59:24.257Z.