CVE-2026-56326: Nuxt URL-handling Weaknesses Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-c9cv-mq2m-ppp3",
  "modified" : "2026-09-18T20:42:57Z",
  "published" : "2026-06-16T13:47:52Z",
  "aliases" : [ "CVE-2026-56326" ],
  "summary" : "Nuxt: URL-handling weaknesses in `navigateTo` and `reloadNuxtApp`: SSR open redirect, client-side script execution via the `open` option, and protocol-relative bypass in `reloadNuxtApp`",
  "details" : "### Summary\n\nThree weaknesses in Nuxt's client-navigation URL handling, all reachable\nfrom documented public APIs (`navigateTo` and `reloadNuxtApp`):\n\n1. **(CVE-2026-56326) SSR open redirect in `navigateTo` via path-normalisation bypass.** \n   `navigateTo` decided whether a target was external by inspecting the raw\n   input with `hasProtocol(..., { acceptRelative: true })`. Inputs such as\n   `/..//evil.com`, `/.//evil.com`, `/%2e%2e//evil.com`, or\n   `/app/..//evil.com` slipped past that check because they start with\n   `/`, but WHATWG URL parsing then normalised them to the\n   protocol-relative pathname `//evil.com`. The normalised value was\n   written to the `Location` response header and into the\n   `<meta http-equiv=\"refresh\">` body of the SSR redirect page, so a\n   victim's browser would resolve the redirect cross-origin to the\n   attacker's host.\n\n2. **(CVE-2026-56698) Client-side script execution via `navigateTo({ open: ... })`.** The\n   client-side early-open handler called `window.open(toPath, ...)` without\n   applying the `isScriptProtocol` check that gates the normal `navigateTo`\n   path. A target of `javascript:...` (or another script-capable scheme)\n   passed to `navigateTo(url, { open: { ... } })` therefore executed in the\n   application's origin instead of being rejected.\n\n3. **(CVE-2026-56697) Open redirect in `reloadNuxtApp` via protocol-relative bypass.**\n   `reloadNuxtApp({ path })` rejects script-capable protocols by parsing\n   the path with `new URL(path, window.location.href)` and checking the\n   resolved `protocol` against `isScriptProtocol`. Protocol-relative paths\n   such as `//evil.com` resolve to the current page's protocol (`https:`),\n   which passes that check; the value is then assigned to\n   `window.location.href`, which the browser treats as a cross-origin\n   redirect. This is the same protocol-relative bypass family as (1), in\n   a different sink.\n\n### Impact\n\nFor (1), the practical risk is phishing or OAuth-code theft against any\nNuxt app that forwards user-controlled input (for example a `?next=`\nquery parameter on a login route) into `navigateTo` on the server. The\nframework documents that `navigateTo` blocks external hosts unless\n`external: true` is passed, so maintainers commonly rely on it as the\nsafe path for post-login redirects.\n\nFor (2), any app that passes a user-controlled URL into\n`navigateTo(url, { open: { ... } })` was vulnerable to reflected XSS in\nthe application's first-party origin.\n\nFor (3), any app that forwards user-controlled input into\n`reloadNuxtApp({ path })` could be redirected cross-origin for phishing\nor OAuth-code theft, even on releases that already shipped the\n`isScriptProtocol` guard added by [#35115](https://github.com/nuxt/nuxt/pull/35115).\n\n### Patches\n\nFixed in `nuxt@4.4.7` and backported to `nuxt@3.21.7`. The three sinks\nare addressed by:\n\n- Path-normalisation bypass in `navigateTo`:\n  - 4.x: commit [`2cce6fb0`](https://github.com/nuxt/nuxt/commit/2cce6fb02e621196d56df92e05594e07469b5a6d)\n  - 3.x: commit [`1f2dd5e7`](https://github.com/nuxt/nuxt/commit/1f2dd5e78c77576437138e97671965573c232835)\n- `navigateTo({ open })` script-protocol guard:\n  - 4.x: [#35206](https://github.com/nuxt/nuxt/pull/35206) (commit [`3394716d`](https://github.com/nuxt/nuxt/commit/3394716d4a913cba904b028df5338f2aead50032))\n  - 3.x: commit [`62fc32ed`](https://github.com/nuxt/nuxt/commit/62fc32eddf648b00a3890141e0235d2a222b024d)\n- Protocol-relative bypass in `reloadNuxtApp`:\n  - 4.x: commit [`e447a793`](https://github.com/nuxt/nuxt/commit/e447a793c47766834f7497f8412a76cd56fd8ee1)\n  - 3.x: commit [`6497d99d`](https://github.com/nuxt/nuxt/commit/6497d99dd106254abd089f6a263d7773869a343b)\n\n### Workarounds\n\n- For (1): validate redirect targets before passing them to `navigateTo`,\n  for example reject any input where\n  `new URL(target, 'http://localhost').pathname` starts with `//`, or\n  only accept a known allow-list of paths.\n- For (2): reject any user-controlled URL whose protocol is not in an\n  allow-list (typically just `http:` and `https:`) before passing it to\n  `navigateTo({ open: ... })`.\n- For (3): same shape as (1). Reject paths starting with `//` (or where\n  `new URL(path, window.location.href).host !== window.location.host`)\n  before passing to `reloadNuxtApp({ path })`.\n\n### References\n\n- CWE-601: URL Redirection to Untrusted Site ('Open Redirect')\n- CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')\n\n### Credits\n\nReported by Anthropic / Claude as `ANT-2026-S08HN6DH` through Anthropic's\ncoordinated vulnerability disclosure programme.\n\nThe `reloadNuxtApp` protocol-relative bypass (sink 3) was independently\nreported by [@alcls01111](https://github.com/alcls01111) via GitHub's\ncoordinated disclosure flow (`GHSA-w7fp-2cfv-4837`), closed as a\nduplicate of this advisory.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:L/SA: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" : "3.5.0"
      }, {
        "fixed" : "3.21.7"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/security/advisories/GHSA-c9cv-mq2m-ppp3"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-56326"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-56697"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-56698"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/pull/35115"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/pull/35206"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/commit/1f2dd5e78c77576437138e97671965573c232835"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/commit/2cce6fb02e621196d56df92e05594e07469b5a6d"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/commit/3394716d4a913cba904b028df5338f2aead50032"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/commit/62fc32eddf648b00a3890141e0235d2a222b024d"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/commit/6497d99dd106254abd089f6a263d7773869a343b"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/commit/e447a793c47766834f7497f8412a76cd56fd8ee1"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/nuxt/nuxt"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/nuxt-cross-site-scripting-via-navigateto-open-option"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/nuxt-open-redirect-via-protocol-relative-paths-in-reloadnuxtapp"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/nuxt-server-side-open-redirect-via-path-normalization-bypass-in-navigateto"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-601", "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-16T13:47:52Z",
    "nvd_published_at" : "2026-06-22T22:16:52Z"
  }
}