Heap-based buffer overflow in Microsoft Windows - CVE-2026-69777
Published: September 8, 2026
Vulnerability identifier: #VU147945
CSH Severity: Medium
CVSS v4: 8.6 [CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-69777
CWE-ID: CWE-122
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to elevate privileges.
The vulnerability exists due to a heap-based buffer overflow in Windows DHCP Client when processing DHCP traffic over an adjacent network. A remote user can send DHCP traffic that triggers the vulnerability to elevate privileges.
Successful exploitation can elevate privileges from Medium Integrity Level to Local Service.
Affected software
Microsoft Windows
How to mitigate CVE-2026-69777
Install security update from vendor's website.
Microsoft Windows - addressed in versions 11 24H2 10.0.26100.9445, 11 25H2 10.0.26200.9445, 11 26H1 10.0.28000.2954