# CVE-2026-16723: Remote Code Execution in fastjson 1.2.68–1.2.83

- Exploited (CISA KEV): no
- Published: 2026-07-23
- CVSS: 9 CRITICAL (v3.1)
- EPSS: 0.7% (52th percentile)
- CWE: CWE-20, CWE-502

A remote code execution (RCE) vulnerability exists in fastjson 1.2.68 through 1.2.83. This vulnerability is exploitable under fastjson's stock default configuration — no AutoType enablement required, no classpath gadget required.

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

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | No public claim | — | — |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | No public claim | — | — |
| Fastly | Before feed history | — | — |
| F5 | Rule published | 2026-09-16 | 55 |
| Akamai | No public source | — | — |
| OWASP CRS | No public claim | — | — |

### F5

- 2026-09-16 · new · rule 200204087
  > Added: signature 200204087 "Fastjson Remote Code Execution" (Server Side Code Injection, risk High), systems: Java Servlets/JSP. References: CVE-2026-16723.
  Source: https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog

"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-2026-16723 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2026-16723