CVE-2026-56301

Nuxt 4.0.0 before 4.4.7 and 3.18.0 before 3.21.7, when running the development server (nuxt dev) on Linux, binds the vite-node IPC server to an abstract-namespace Unix socket without permission restrictions, allowing local users to enumerate and connect. Unprivileged co-resident users can exploit the unprotected module request handler to read arbitrary files such as .env and SSH keys through the SSR plugin pipeline. Production builds are unaffected, as the IPC server runs only in development.

Nuxt 4.0.0 before 4.4.7 and 3.18.0 before 3.21.7, when running the development server (nuxt dev) on Linux, binds the vite-node IPC server to an abstract-namespace Unix socket without permission restrictions, allowing local users to enumerate and connect. Unprivileged co-resident users can exploit the unprotected module request handler to read arbitrary files such as .env and SSH keys through the SSR plugin pipeline. Production builds are unaffected, as the IPC server runs only in development.

Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-534h-c3cw-v3h9. This link is maintained to preserve external references.

Original Description

Nuxt 4.0.0 before 4.4.7 and 3.18.0 before 3.21.7, when running the development server (nuxt dev) on Linux, binds the vite-node IPC server to an abstract-namespace Unix socket without permission restrictions, allowing local users to enumerate and connect. Unprivileged co-resident users can exploit the unprotected module request handler to read arbitrary files such as .env and SSH keys through the SSR plugin pipeline. Production builds are unaffected, as the IPC server runs only in development.

Impact

When running nuxt dev on Linux (Node.js 20+, outside Docker / StackBlitz), Nuxt's internal vite-node IPC server binds to a Linux abstract-namespace Unix socket (\0nuxt-vite-node-<pid>-<ts>.sock). Abstract sockets have no filesystem inode and therefore no permission bits: any local UID on the host that can read /proc/net/unix can enumerate the socket and connect to it.

The IPC server does not perform any peer-credential or shared-secret check before dispatching requests. The module request type passes its moduleId field straight into Vite's SSR fetchModule(), which is not gated by Vite's HTTP-layer server.fs.allow deny-list. A co-resident unprivileged local user can therefore request paths like /home/<dev>/project/.env?raw or ~/.ssh/id_rsa?raw and read the developer's secrets through the dev server's SSR plugin pipeline. The resolve request type additionally enables filesystem probing.

This affects developers running nuxt dev on shared multi-tenant Linux hosts (lab machines, shared bastions, CI runners shared between jobs without per-job container isolation). It does not affect:

• Production builds (nuxt build / nuxt start). The IPC server only runs in development.
• macOS or Windows developers.
• Docker / StackBlitz environments, which already fall back to a filesystem socket.
• Single-user laptops or per-job containerised CI.

Patches

Fixed in [email protected] (commit 1f9f4767) and backported to [email protected] (commit c293bf95).

The fix removes the abstract-namespace branch entirely. The IPC server now always binds to a filesystem Unix socket under the OS temp directory and explicitly chmod 0600s it after listen(), restricting connections to the owning UID. If the chmod fails for any reason, the server closes rather than serve requests on an unrestricted channel.

Workarounds

If you cannot upgrade immediately on an affected host:

• Run nuxt dev inside a container or VM with no other tenants. Docker already triggers the filesystem-socket fallback in vulnerable versions and that fallback is unaffected.
• Bind the dev process to a single-user namespace (unshare -U, rootless containers).
• Restrict /proc/net/unix visibility via hidepid=2 mount options where applicable, though this is partial mitigation only.

References

• Affected file: packages/vite/src/plugins/vite-node.ts
• CWE-276: Incorrect Default Permissions

Credit

Reported by Anthropic / Claude as part of Anthropic's coordinated vulnerability disclosure programme, reference ANT-2026-MSNKZFAT. Thanks to the Anthropic security team for the report and the detailed reproduction.

Independently reported by @alcls01111 via GitHub's coordinated disclosure flow (GHSA-5gvc-46gq-948j), closed as a duplicate of this advisory.

Summary

When running nuxt dev, Nuxt registers an unauthenticated route at /.well-known/appspecific/com.chrome.devtools.json that returns the absolute filesystem path of the project root and a per-project UUID persisted to node_modules/.cache/nuxt/chrome-workspace.json. The route is enabled by default via experimental.chromeDevtoolsProjectSettings: true.

The endpoint exists to let Chrome DevTools' Workspace integration map sources to the developer's local checkout. The handler is registered directly on nitro.options.devHandlers and does not pass through the CORS / origin wrapper that the rest of the dev pipeline uses, so it has no host / origin / Sec-Fetch-Site check of its own.

Impact

Dev-server only. Production builds do not register the route.

Two values are disclosed:

• workspace.root: the absolute filesystem path of the project (commonly reveals the OS username and the on-disk project name).
• workspace.uuid: a v4 UUID persisted to node_modules/.cache/nuxt/chrome-workspace.json, stable across dev-server restarts and re-clones.

Threat model

The response carries no Access-Control-Allow-Origin header. A cross-origin fetch() from an arbitrary malicious page is therefore blocked by the browser's same-origin policy and cannot read the body. The two realistic recovery paths are:

1. LAN-adjacent attacker when the developer runs nuxt dev --host (or otherwise binds to a non-loopback interface). A plain curl http://<dev-lan-ip>:3000/.well-known/appspecific/com.chrome.devtools.json returns the JSON; no browser, no CORS.
2. DNS rebinding against the default loopback dev server. A page the developer visits resolves to the attacker, then re-resolves to 127.0.0.1 after the TTL; the browser believes the request is same-origin and reads the response.

Affected versions

[email protected] (PR #32084) through [email protected]. 3.x is not affected.

Reproduction

npx nuxt dev
curl -s http://localhost:3000/.well-known/appspecific/com.chrome.devtools.json
# {"workspace":{"uuid":"...","root":"/Users/<name>/..."}}

Workaround

Set experimental: { chromeDevtoolsProjectSettings: false } in nuxt.config.ts. Chrome DevTools' Workspace auto-integration will stop working; the dev server is otherwise unaffected.

Patches

Fixed in [email protected] by #35201 (commit 55c75b78). The handler is now routed through the same host / origin gate the rest of the dev server uses, so the endpoint only responds to requests that look local.

Nuxt 4.0.0 before 4.4.7 and 3.18.0 before 3.21.7, when running the development server (nuxt dev) on Linux, binds the vite-node IPC server to an abstract-namespace Unix socket without permission restrictions, allowing local users to enumerate and connect. Unprivileged co-resident users can exploit the unprotected module request handler to read arbitrary files such as .env and SSH keys through the SSR plugin pipeline. Production builds are unaffected, as the IPC server runs only in development.