Out-of-bounds read in Microsoft Windows and Windows Server - CVE-2026-85369
Published: October 14, 2026
Vulnerability identifier: #VU155131
CSH Severity: Low
CVSS v4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-85369
CWE-ID: CWE-125
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local privileged user to escalate privileges to SYSTEM and execute arbitrary code on the Hyper-V host operating system.
The vulnerability exists due to an out-of-bounds read in Windows Hyper-V when processing vSMB packet data. A local privileged user can run a specially crafted application on a Hyper-V guest to escalate privileges to SYSTEM and execute arbitrary code on the Hyper-V host operating system.
Affected software
Microsoft Windows
Windows Server
Windows Server
How to mitigate CVE-2026-85369
Install security update from vendor's website.
Microsoft Windows - addressed in versions 10 21H2 10.0.19044.7807, 11 23H2 10.0.22631.7652, 11 24H2 10.0.26100.9711, 11 25H2 10.0.26200.9711, 11 26H1 10.0.28000.3231
Windows Server - addressed in versions 2022 10.0.20348.5761, 2025 10.0.26100.33650
Windows Server - addressed in versions 2022 10.0.20348.5761, 2025 10.0.26100.33650