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PatchSiren cyber security CVE debrief

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.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-34335 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-34335

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-34335 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-34335

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.