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PatchSiren cyber security CVE debrief

CVE-2026-42911 Microsoft CVE debrief

CVE-2026-42911 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 CVSS score for this vulnerability is 7.0, with a CVSS vector of CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.

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
2026-06-11
Advisory published
2026-06-09
Advisory updated
2026-06-11

Who should care

Administrators and users of Windows operating systems should be aware of this vulnerability, as it can be exploited by an authorized attacker to elevate privileges locally.

Technical summary

The vulnerability is caused by a use-after-free issue in Windows Ancillary Function Driver for WinSock. This issue allows an authorized attacker to elevate privileges locally.

Defensive priority

HIGH

Recommended defensive actions

  • Apply patches from Microsoft as soon as possible.
  • See ${ref-4} for vendor advisory.

Evidence notes

The CVE record for CVE-2026-42911 was obtained from ${cve-org}. The NVD detail for CVE-2026-42911 was obtained from ${nvd}.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-42911 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-42911

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

  • CVE-2026-42911 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-42911

    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.