Use-after-free in Microsoft Windows and Windows Server - CVE-2026-119947
Published: November 11, 2026
Vulnerability identifier: #VU165368
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-119947
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local privileged user to escalate privileges from a guest virtual machine to the host.
The vulnerability exists due to use-after-free in Windows Hyper-V when handling guest virtual machine operations. A local privileged user can exploit access to freed memory from within a guest virtual machine to execute code on the host in the security context of the virtual machine worker process.
Successful exploitation requires winning a race condition.
Affected software
Microsoft Windows
Windows Server
Windows Server
How to mitigate CVE-2026-119947
Install security update from vendor's website.
Microsoft Windows - addressed in versions 10 21H2 10.0.19044.7846, 10 22H2 10.0.19045.7846, 10 1607 10.0.14393.9688, 10 1809 10.0.17763.9487, 11 23H2 10.0.22631.7711, 11 24H2 10.0.26100.9911, 11 24H2 10.0.26100.9974, 11 25H2 10.0.26200.9911, 11 25H2 10.0.26200.9974, 11 26H1 10.0.28000.3501
Windows Server - addressed in versions 2016 10.0.14393.9688, 2019 10.0.17763.9487, 2022 10.0.20348.5870, 2025 10.0.26100.33730, 2025 10.0.26100.33822
Windows Server - addressed in versions 2016 10.0.14393.9688, 2019 10.0.17763.9487, 2022 10.0.20348.5870, 2025 10.0.26100.33730, 2025 10.0.26100.33822