# CVE-2021-43226: Microsoft Windows Privilege Escalation Vulnerability

- Exploited (CISA KEV): yes, added 2025-10-06, known ransomware use
- Published: 2021-12-15
- CVSS: 7.8 HIGH (v3.1)
- EPSS: 3.3% (88th percentile)

Windows Common Log File System Driver Elevation of Privilege Vulnerability

## Edge WAF coverage (claimed by vendors, not measured)

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | Before feed history | — | — |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | Before feed history | — | — |
| Fastly | Before feed history | — | — |
| F5 | Before feed history | — | — |
| Akamai | No public source | — | — |
| OWASP CRS | Before feed history | — | — |

"No public claim" means no vendor statement names this CVE; "Before feed history" means the CVE is older than the vendor feed. In both cases generic rules may still block it.

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