CVE-2024-34351

Prerequisites

• Next.js (<14.1.1) is running in a self-hosted* manner.
• The Next.js application makes use of Server Actions.
• The Server Action performs a redirect to a relative path which starts with a /.

* Many hosting providers (including Vercel) route requests based on the Host header, so we do not believe that this vulnerability affects any Next.js applications where routing is done in this manner.

Workarounds

There are no official workarounds for this vulnerability. We recommend upgrading to Next.js 14.1.1.

Credit

Vercel and the Next.js team thank Assetnote for responsibly disclosing this issue to us, and for working with us to verify the fix. Thanks to:

Adam Kues - Assetnote
Shubham Shah - Assetnote

A Server-Side Request Forgery (SSRF) vulnerability was identified in Next.js Server Actions by security researchers at Assetnote. If the Host header is modified, and the below conditions are also met, an attacker may be able to make requests that appear to be originating from the Next.js application server itself.

Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside. Typical impact: access to internal metadata services, internal APIs, or cloud credentials.

CVE-2024-34351 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (14.1.1); upgrading removes the vulnerable code path.

Kodem intelligence

This vulnerability was patched in #62561 and fixed in Next.js 14.1.1.

1. What is CVE-2024-34351? CVE-2024-34351 is a high-severity server-side request forgery (SSRF) vulnerability in next (npm), affecting versions >= 13.4.0, < 14.1.1. It is fixed in 14.1.1. Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside.
2. How severe is CVE-2024-34351? CVE-2024-34351 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of next are affected by CVE-2024-34351? next (npm) versions >= 13.4.0, < 14.1.1 is affected.
4. Is there a fix for CVE-2024-34351? Yes. CVE-2024-34351 is fixed in 14.1.1. Upgrade to this version or later.
5. Is CVE-2024-34351 exploitable, and should I be worried? Whether CVE-2024-34351 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2024-34351 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2024-34351? Upgrade next to 14.1.1 or later.