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CVE-2026-45641 Microsoft CVE debrief

CVE-2026-45641 is a HIGH severity vulnerability in Windows Hyper-V that allows an unauthorized attacker to execute code locally. The vulnerability has a CVSS score of 8.4 and was published on 2026-06-09T17:17:31.100Z. The vulnerability was modified on 2026-06-11T17:42:07.063Z.

Vendor
Microsoft
Product
Windows 10 Version 21H2
CVSS
HIGH 8.4
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 Hyper-V are advised to take immediate action to mitigate this vulnerability.

Technical summary

The vulnerability is an out-of-bounds read in Windows Hyper-V, which allows an unauthorized attacker to execute code locally. The vulnerability affects multiple versions of Windows, including Windows 10, Windows 11, and Windows Server.

Defensive priority

HIGH

Recommended defensive actions

  • Apply patches from Microsoft as soon as possible.
  • Refer to [ref-4](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45641) for mitigation or vendor reference.

Evidence notes

The vulnerability is analyzed and has a CVSS vector of CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Official resources

CVE-2026-45641 was published on 2026-06-09T17:17:31.100Z and modified on 2026-06-11T17:42:07.063Z.