CVE-2026-53722: Nuxt Cross-Site Scripting Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-934w-87qh-qr26",
  "modified" : "2026-08-14T18:45:56Z",
  "published" : "2026-06-16T13:49:36Z",
  "aliases" : [ "CVE-2026-53722" ],
  "summary" : "Nuxt: Reflected XSS in `<NuxtLink>` via unsanitised `javascript:` or `data:` URL",
  "details" : "### Summary\n\n`<NuxtLink>` did not validate the URL scheme of values bound to its `to` or `href` props before rendering them into the `href` attribute of the underlying `<a>` element. When an application binds attacker-controlled input (a query parameter, a CMS field, a user-supplied profile URL) to `<NuxtLink :to>` or `:href`, the attacker can supply a `javascript:` or `vbscript:` URL that is reflected verbatim into the rendered markup. Clicking the link executes the supplied script in the origin of the Nuxt application, resulting in reflected DOM-based cross-site scripting. A `data:text/html,...` payload reflected through the same sink does not execute in the application's origin but enables a same-tab phishing surface anchored to a legitimate application link.\n\nThe same value was exposed to consumers of the component's `custom` slot via the `href` and `route.href` props, so applications that re-bind those values to their own anchors were affected identically.\n\nUnlike the previously reported `navigateTo` issue (CVE-2024-34343), the sink here is the rendered anchor itself; the existing `isScriptProtocol` checks in `navigateTo` and `reloadNuxtApp` are not on the code path. The `onClick` handler intentionally returns early for external links so the browser's native protocol-based navigation runs.\n\n### Affected component\n\n- File: `packages/nuxt/src/app/components/nuxt-link.ts`\n- Sink: `h('a', { href: href.value, ... })` in the default render, plus the `href` / `route.href` props passed to the `custom` slot.\n- Broken check: external auto-detection treated any `hasProtocol(path, { acceptRelative: true })` value as an \"external link\", then rendered the value directly as `<a href>` without rejecting script-capable protocols. There was no equivalent of the `navigateTo` `isScriptProtocol(protocol)` gate in this path.\n\n### Impact\n\nAny Nuxt application that binds user-controlled values to `<NuxtLink :to>` / `:href` was vulnerable. Common shapes: profile-link rendering (`<NuxtLink :to=\"user.website\">`), \"share this\" / \"open in new tab\" handlers that pass through a query parameter, CMS-driven landing pages that render `<NuxtLink :to=\"cms.cta.url\">`, and marketplace listings that show seller-supplied links.\n\nFor `javascript:` / `vbscript:` the primitive is reflected XSS in the application's first-party origin (session theft for non-`HttpOnly` cookies, CSRF token theft, account takeover via DOM rewriting, credential harvesting via fake login overlays). For `data:text/html,...` the attacker gets a same-tab phishing surface anchored to a legitimate application link.\n\n### Patches\n\nFixed in `nuxt@4.4.7` (commit [`0103ce06`](https://github.com/nuxt/nuxt/commit/0103ce06fbbbdfa079a7f020ef8ce00121eac4a3)) and backported to `nuxt@3.21.7` (commit [`53284043`](https://github.com/nuxt/nuxt/commit/53284043dc21210a25d629d1cec67d3ae557ffd0)). The fix sanitises the resolved external `href` before it is passed to `<a>` or the `custom` slot: control characters and whitespace are stripped, leading `view-source:` prefixes are unwrapped, and any remaining script-capable scheme (per `isScriptProtocol`) causes the `href` to be replaced with an empty string.\n\n### Workarounds\n\nUntil you can upgrade, validate URLs at the source before binding them to `<NuxtLink :to>` / `:href`. For example, only accept paths that start with `/` (and not `//`), or run user-supplied URLs through `new URL(value)` and reject anything whose `protocol` is not in an allow-list (typically `http:` and `https:`).",
  "severity" : [ {
    "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:N/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" : "3.0.0"
      }, {
        "fixed" : "3.21.7"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/security/advisories/GHSA-934w-87qh-qr26"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-53722"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/commit/0103ce06fbbbdfa079a7f020ef8ce00121eac4a3"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/commit/53284043dc21210a25d629d1cec67d3ae557ffd0"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/nuxt/nuxt"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79", "CWE-83" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-16T13:49:36Z",
    "nvd_published_at" : "2026-06-12T15:16:31Z"
  }
}