---
cve: "CVE-2026-64649"
severity: "HIGH"
cvss: 8.3
epss: "54%"
vendor: "vercel"
kev: false
exploited: false
published: "2026-07-27 20:16:40"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-03T11:01:16+02:00"
---

# CVE-2026-64649

> 8.3 HIGH · 🧪 PoC

## Beschreibung

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.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- e26f6ffaa710fc62ca0c8640db0e43b6663edf32 (Commit)
- 9beca0821cf4606ae33466ed6f4fc75f2887a4da (Commit)

## Referenzen

- <https://github.com/vercel/next.js/security/advisories/GHSA-89xv-2m56-2m9x>
- <https://github.com/vercel/next.js/commit/b51206321854193208c0805ba42acc49287f942b>
- <https://github.com/vercel/next.js/commit/e3e5666ccead3a15162793d697af5e48b7cc0498>
- <https://github.com/vercel/next.js/releases/tag/v15.5.21>
- <https://github.com/vercel/next.js/releases/tag/v16.2.11>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-64649) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_