# CVE-2026-21643: Fortinet FortiClient EMS SQL Injection Vulnerability

- Exploited (CISA KEV): yes, added 2026-04-13
- Published: 2026-02-06
- CVSS: 9.1 CRITICAL (v3.1)
- EPSS: 97.7% (100th percentile)
- CWE: CWE-89

An improper neutralization of special elements used in an sql command ('sql injection') vulnerability in Fortinet FortiClientEMS 7.4.4 may allow an unauthenticated attacker to execute unauthorized code or commands via specifically crafted HTTP requests.

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

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | Blocks by default | 2026-04-15 | 68 |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | No public claim | — | — |
| Fastly | Before feed history | — | — |
| F5 | Rule published | 2026-07-07 | 151 |
| Akamai | No public source | — | — |
| OWASP CRS | No public claim | — | — |

### Cloudflare

- 2026-04-15 · new · rule 3dd0b2b6f45c4bc08e49bf27ee7be621 · default Block
  > FortiClient EMS - Pre-Auth SQL Injection - CVE:CVE-2026-21643. Previous action: Log. New action: Block. This is a new detection.
  Source: https://developers.cloudflare.com/changelog/post/2026-04-15-waf-release/

### F5

- 2026-07-07 · new · rule 200102208
  > Added: signature 200102208 "FortiClient EMS SQL Injection" (SQL-Injection, risk High), systems: Other Web Server. References: CVE-2026-21643.
  Source: https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog

## Our test (measured)

- OWASP Core Rule Set 4.25.0, paranoia level 1, anomaly threshold 5, default CRS settings: passed (0 of 2 requests blocked), template CVE-2026-21643, 2026-11-02
- OWASP Core Rule Set 4.25.0, paranoia level 2, anomaly threshold 5, default CRS settings: passed (0 of 2 requests blocked), template CVE-2026-21643, 2026-11-02

"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.

HTML: https://cve.vigilbase.com/cve/CVE-2026-21643 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2026-21643