CVE-2026-83939: Microsoft Windows 11 26h1

High severity, CVSS 8.2. EPSS: 0.3% chance of exploitation in the next 30 days.

Untrusted pointer dereference in Windows Secure Kernel Mode allows an authorized attacker to elevate privileges locally.

Affected products

• Microsoft Windows 11 26h1: before 10.0.28000.2954 (fixed in 10.0.28000.2954)

Published 2026-09-08. Last modified 2026-09-10.