Out-of-bounds read in Microsoft Windows and Windows Server - CVE-2026-77891
Published: September 9, 2026
Vulnerability identifier: #VU148190
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-2026-77891
CWE-ID: CWE-125
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local privileged user to execute code.
The vulnerability exists due to an out-of-bounds read in Windows DHCP Server when exploited locally. A local privileged user can exploit the vulnerability to execute code.
Successful exploitation requires a deep understanding of the system and depends on environmental and system-configuration factors.
Affected software
Microsoft Windows
Windows Server
Windows Server
How to mitigate CVE-2026-77891
Install security update from vendor's website.
Microsoft Windows - addressed in versions 10 1607 10.0.14393.9512, 10 1809 10.0.17763.9245
Windows Server - addressed in versions 2012 R2 6.3.9600.23397, 2012 6.2.9200.26349, 2016 10.0.14393.9512, 2019 10.0.17763.9245, 2022 10.0.20348.5622, 2025 10.0.26100.33438
Windows Server - addressed in versions 2012 R2 6.3.9600.23397, 2012 6.2.9200.26349, 2016 10.0.14393.9512, 2019 10.0.17763.9245, 2022 10.0.20348.5622, 2025 10.0.26100.33438