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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}.

Official resources

CVE-2026-42911 was published on ${cvePublishedAt} and modified on ${cveModifiedAt}.