CVE-2026-2636
clfs.sys — improper flag validation causes denial of service (BSoD)
Summary
| Field | Value |
|---|---|
| Driver | clfs.sys |
| Vulnerability Class | Denial of Service (Improper Validation) |
| CVSS | 6.2 |
| Exploited ITW | No (PoC public) |
| Patch Date | February 11, 2026 |
Root Cause
The CLFS driver skips flag validation in log file metadata. A crafted log file with invalid flag combinations triggers an unrecoverable kernel panic (BSoD). A public PoC exists demonstrating the crash.
Exploitation
The attacker creates a crafted CLFS log file with invalid flags. When the driver processes the file, it triggers a bug check (BSoD). DoS only, no code execution.
Exploitation Primitive
Crafted CLFS log file → invalid flag validation
→ kernel panic (BSoD)