# CVE-2026-64649: Next.js: Server-Side Request Forgery in Server Actions on Custom Servers

- Exploited (CISA KEV): no
- Published: 2026-07-27
- CVSS: 8.3 HIGH (v4.0)
- EPSS: 0.5% (40th percentile)
- CWE: CWE-918

Next.js is a React framework for building full-stack web applications. In versions 14.1.1 through 15.5.20 and 16.0.0 through 16.2.10, when a Server Action forwards or redirects a request, an attacker can cause the server to send that outbound request to a malicious host (Server-Side Request Forgery). This requires the attacker's request to control Host-associated headers. In some configurations, it's also possible to obtain internal values that weaken middleware/proxy authorization. Applications that use Server Actions are affected when the incoming host header is not fixed to a trusted value. This typically occurs on custom servers, or on deployments not behind a proxy that pins the host. Managed hosting pins the host upstream and is not affected; next start and standalone output do the same from version 14.2 onward. This issue has been fixed in versions 15.5.21 and 16.2.11.

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

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | Blocks by default | 2026-07-21 | — |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | No public claim | — | — |
| Fastly | Before feed history | — | — |
| F5 | No public claim | — | — |
| Akamai | No public source | — | — |
| OWASP CRS | No public claim | — | — |

### Cloudflare

- 2026-07-21 · updated · rule 7fe6d6f3df774ae2a0011f20930091a3 · default Block
  > Next.js - SSRF - CVE-2026-64649. Previous action: N/A. New action: Block. This was labeled as Generic Rules - Auth Bypass - 2.
  Source: https://developers.cloudflare.com/changelog/post/2026-07-21-waf-release/

"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-2026-64649 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2026-64649