CVE-2026-94485: Next.js: Information disclosure in Next.js App Router metadata image routes via dynamicParams bypass
In Next.js App Router applications built with webpack, metadata image routes such as opengraph-image and twitter-image ignore the dynamicParams route segment option. An attacker can request metadata image URLs for dynamic segments that were deliberately excluded from generateStaticParams().
Other sources
Next.js is a React framework for building full-stack web applications. From 16.0.0 until 16.3.8, the next dev development server exposes a Model Context Protocol endpoint without reliably restricting cross-site requests. A malicious website visited by a developer can reach the endpoint and read the project's disk location, source code snippets from error reports, route inventory, and development logs. Production deployments do not serve this endpoint. This issue is fixed in version 16.3.8.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
npm/nextto a version that resolves this vulnerability.Fixed in 16.3.8 - Upgrade
Upgrade
Next.jsto a version that resolves this vulnerability.Fixed in 16.3.8
Event History
Frequently Asked Questions
Who is exposed to this issue?
Developers running the Next.js development server with versions from 16.0.0 through 16.3.8 are exposed if they visit a malicious website. Production deployments are not affected because they do not serve the vulnerable endpoint.
What does an attacker need to exploit it?
The attacker needs a developer using an affected Next.js development server to visit a malicious website. The website can then make cross-site requests to the development server's Model Context Protocol endpoint.
What information could be disclosed?
The exposed endpoint can disclose the project's disk location, source code snippets contained in error reports, the route inventory, and development logs.
What should teams do if they are using an affected version?
Upgrade Next.js to version 16.3.8, which fixes the issue. Until upgraded, avoid visiting untrusted websites while an affected Next.js development server is running.