CVE-2026-56301: Nuxt Nuxt Dev Server Vite-node IPC Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-534h-c3cw-v3h9",
  "modified" : "2026-09-23T21:25:56Z",
  "published" : "2026-06-16T13:49:10Z",
  "aliases" : [ "CVE-2026-56301" ],
  "summary" : "Nuxt dev server vite-node IPC socket is world-connectable on Linux",
  "details" : "### Impact\n\nWhen 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.\n\nThe 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.\n\nThis 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:\n\n- Production builds (`nuxt build` / `nuxt start`). The IPC server only runs in development.\n- macOS or Windows developers.\n- Docker / StackBlitz environments, which already fall back to a filesystem socket.\n- Single-user laptops or per-job containerised CI.\n\n### Patches\n\nFixed in `nuxt@4.4.7` (commit [`1f9f4767`](https://github.com/nuxt/nuxt/commit/1f9f4767a8725104da9bee872bb8d35246f25ae5)) and backported to `nuxt@3.21.7` (commit [`c293bf95`](https://github.com/nuxt/nuxt/commit/c293bf9503ccb3bc9559bff4a1f592f99063c9ea)).\n\nThe 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 0600`s 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.\n\n### Workarounds\n\nIf you cannot upgrade immediately on an affected host:\n\n- 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.\n- Bind the dev process to a single-user namespace (`unshare -U`, rootless containers).\n- Restrict `/proc/net/unix` visibility via `hidepid=2` mount options where applicable, though this is partial mitigation only.\n\n### References\n\n- Affected file: `packages/vite/src/plugins/vite-node.ts`\n- CWE-276: Incorrect Default Permissions\n\n### Credit\n\nReported 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.\n\nIndependently reported by [@alcls01111](https://github.com/alcls01111) via GitHub's coordinated disclosure flow (`GHSA-5gvc-46gq-948j`), closed as a duplicate of this advisory.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "nuxt"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.0.0"
      }, {
        "fixed" : "4.4.7"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "nuxt"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.18.0"
      }, {
        "fixed" : "3.21.7"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/security/advisories/GHSA-534h-c3cw-v3h9"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-56301"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/commit/1f9f4767a8725104da9bee872bb8d35246f25ae5"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/commit/c293bf9503ccb3bc9559bff4a1f592f99063c9ea"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/nuxt/nuxt"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/nuxt-arbitrary-file-read-via-world-connectable-vite-node-ipc-socket-on-linux"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-276" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-16T13:49:10Z",
    "nvd_published_at" : null
  }
}