CVE-2026-21231
ntoskrnl.exe — race condition with improper synchronization allows SYSTEM escalation
Exploited in the Wild
Actively exploited. Added to CISA KEV with remediation deadline March 3, 2026.
Summary
| Field | Value |
|---|---|
| Driver | ntoskrnl.exe |
| Vulnerability Class | Race Condition |
| CVSS | 7.8 |
| Exploited ITW | Yes |
| Patch Date | February 10, 2026 |
Root Cause
Concurrent execution on a shared resource with missing synchronization (CWE-362). An authenticated local attacker wins a race condition on a shared kernel resource to corrupt memory and gain SYSTEM.
Exploitation
The attacker races concurrent threads against a shared kernel resource. Winning the race corrupts kernel memory for privilege escalation.
Exploitation Primitive
Race condition on shared kernel resource → memory corruption → SYSTEM