SB2026061143 - Multiple vulnerabilities in Microsoft Windows Hyper-V

Description

This security bulletin contains information about 4 vulnerabilities.

1) Out-of-bounds read (CVE-ID: CVE-2026-45607)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to a boundary condition in Windows Hyper-V. A remote attacker can send specially crafted file operation requests, trigger an out-of-bounds read error and read contents of memory on the system, leading to arbitrary code execution.

2) Information disclosure (CVE-ID: CVE-2026-42972)

CWE-ID: CWE-200 - Exposure of sensitive information to an unauthorized actor

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to gain access to potentially sensitive information.

The vulnerability exists due to excessive data output by the application in Windows Hyper-V. A local user can gain unauthorized access to sensitive information on the system.

3) Heap-based buffer overflow (CVE-ID: CVE-2026-47652)

CWE-ID: CWE-122 - Heap-based Buffer Overflow

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a remote user to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error in Windows Hyper-V. A remote administrator can pass specially crafted data to the application, trigger a heap-based buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

4) Type Confusion (CVE-ID: CVE-2026-45641)

CWE-ID: CWE-843 - Type confusion

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to a boundary condition in Windows Hyper-V. A remote attacker can send specially crafted file operation requests, trigger an out-of-bounds read error and read contents of memory on the system, leading to arbitrary code execution.

Remediation

Install update from vendor's website.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45607
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42972
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-47652
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45641