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CVE-2026-45601 Microsoft CVE debrief

CVE-2026-45601 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, particularly those using Windows 10, Windows 11, and Windows Server versions.

Technical summary

The vulnerability affects multiple versions of Windows, including Windows 10, Windows 11, and Windows Server. The affected versions include Windows 10 1607, Windows 10 1809, Windows 10 21H2, Windows 10 22H2, Windows 11 23H2, Windows 11 24H2, Windows 11 25H2, Windows 11 26H1, Windows Server 2012, Windows Server 2012 R2, Windows Server 2016, Windows Server 2019, Windows Server 2022, and Windows Server 2025.

Defensive priority

HIGH

Recommended defensive actions

  • Apply patches from Microsoft as soon as possible.
  • Review and update Windows operating systems to the latest versions.
  • Implement additional security measures, such as monitoring and incident response planning.

Evidence notes

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

Official resources

CVE-2026-45601 was published on 2026-06-09T17:17:28.547Z and modified on 2026-06-11T18:47:25.140Z.