CVE-2026-83855 Windows WLAN Service Denial of Service Vulnerability

High 7.5 Published 13 Oct 2026 Updated 29 Oct 2026

An integer underflow in the Windows WLAN Service allows an unauthorized attacker to cause a denial of service over the network.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-83855?

CVE-2026-83855 is a high-severity vulnerability in Microsoft Windows 11 23h2, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Integer underflow (wrap or wraparound) in Windows WLAN Service allows an unauthorized attacker to deny service over a network.

Weakness: CWE-191

Which versions are affected by CVE-2026-83855?

It affects 6 products.

Products include Microsoft Windows 11 23h2, Microsoft Windows 11 24h2, Microsoft Windows 11 25h2, Microsoft Windows 11 26h1, Microsoft Windows 11 26h2, Microsoft Windows Server 2025.

How do I fix CVE-2026-83855?

No fix has been published for CVE-2026-83855 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-83855 being exploited?

There is no known exploitation of CVE-2026-83855 in the wild and no public exploit code.

All Microsoft Windows 11 23h2 vulnerabilities

Sources

Also known as GHSA-86rh-fwj4-9gwg.