Integer underflow in Microsoft Windows and Windows Server - CVE-2026-83855
Published: October 14, 2026
Vulnerability identifier: #VU155003
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-83855
CWE-ID: CWE-191
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to integer underflow in Windows WLAN Service when processing network traffic. A remote attacker can trigger the integer underflow over a network to cause a denial of service.
Affected software
Microsoft Windows
Windows Server
Windows Server
How to mitigate CVE-2026-83855
Install security update from vendor's website.
Microsoft Windows - addressed in versions 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 - update to 2025 10.0.26100.33650
Windows Server - update to 2025 10.0.26100.33650