NEXT · CVE-2026-94486 · Package
FIX → 16.3.8 +1
The Next.js development server exposes a Model Context Protocol endpoint that does not check which website sends a request. A malicious page open in the developer's browser can read the project's disk path, source snippets from error reports, the route list and development logs.
first public Sep 30, 2026 · 3 sources
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Only projects running the development server (next dev) are exposed; production deployments do not serve this endpoint. A developer who visits a malicious website while the dev server runs can have local development data read. Teams that never run next dev on a reachable machine can skip it.
Not affected if no-next-dev, production-only, static-export
Who cares developers, mcp, next.js, npm
next --version in the project and check whether it is 16.0.0 or later and below the fixed version.next dev on a machine a browser can reach.The Next.js development server (next dev) exposes a Model Context Protocol endpoint that does not verify which website a request originates from, allowing a malicious website visited by the developer to read sensitive development data — including the project's location on disk, source code snippets from error reports, the route inventory, and development logs. Only applications run with next dev are affected. Production deployments do not serve this endpoint.
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next version in package.json and the lockfile.Upgrade to 16.3.8 +1
16.3.8GitHub Advisory Database, CC-BY 4.0 · NVD data is provided by NIST and is public domain. Posts quoted belong to their authors.