CVE-2026-71315: Nuxt Nuxt Route Rules Silently Dropped Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-hxvh-4h3w-prp9",
  "modified" : "2026-08-05T21:05:18Z",
  "published" : "2026-08-05T21:05:18Z",
  "aliases" : [ "CVE-2026-71315" ],
  "summary" : "Nuxt route rules silently dropped for mixed-case paths, bypassing appMiddleware auth gates (incomplete fix for CVE-2026-53721)",
  "details" : "### Impact\n\nNuxt matches route rules case-insensitively by default (mirroring vue-router's default `sensitive: false` routing). The fix for GHSA-mm7m-92g8-7m47 / CVE-2026-53721 lowercased the *lookup* path before matching route rules, but the route-rule *keys* compiled into the matcher were left verbatim. As a result, any route rule whose key contains an uppercase character (for example `/Admin`, `/Dashboard/**`, or the rules Nuxt derives from PascalCase/camelCase page files such as `pages/Admin.vue`) never matches, because every lookup is folded to lowercase while the key stays mixed-case.\n\nvue-router still serves the page case-insensitively, so the page renders with none of its Nuxt route-rule protections applied. The most serious consequence is an authorization bypass: an `appMiddleware` rule used as an auth gate (`routeRules: { '/Admin/dashboard': { appMiddleware: 'auth' } }`) is dropped, and `/Admin/dashboard`, `/admin/dashboard`, and `/ADMIN/dashboard` all render the protected page (and its SSR-fetched data) to an unauthenticated visitor instead of redirecting to login. The same gap drops Nuxt's other app-side route-rule behaviours for mixed-case keys, including the client redirect middleware, the app-side `ssr: false` decision, `prerender`, and payload handling.\n\n### Patches\n\nFixed in `nuxt@4.5.1` (4.x) and `nuxt@3.21.10` (3.x). The route-rule matcher now case-folds the compiled keys the same way it folds the lookup path, so key and lookup normalisation are symmetric. Both sides are gated on `router.options.sensitive`: with `sensitive: true` (case-sensitive routing) configured casing is preserved on both sides.\n\nScope note: server-emitted per-route `headers`, server `redirect`, and `proxy` are matched by Nitro's own case-sensitive route-rule matcher, not by Nuxt's app-level matcher. They are unchanged by this advisory. The fix covers the app-level protections Nuxt owns (`appMiddleware`, `appLayout`, the client redirect middleware, the app `ssr` decision, `prerender`, and payload).\n\n### Workarounds\n\nIf you cannot upgrade immediately, any one of:\n\n- Key all `routeRules` (and name your page files) in lowercase, so the keys already match the folded lookup path.\n- Set `router: { options: { sensitive: true } }` so routing and route-rule matching are both case-sensitive and exact (requests must then use the exact casing).\n- Enforce the sensitive protections server-side independently of route rules (for example a server middleware that checks auth), which does not rely on case-insensitive route-rule matching.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "nuxt"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.4.7"
      }, {
        "fixed" : "4.5.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "nuxt"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.21.7"
      }, {
        "fixed" : "3.21.10"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/security/advisories/GHSA-hxvh-4h3w-prp9"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/commit/619963309e082190bac4a26b05f2dd155b039b81"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/commit/ad624a75ad2d215f43633f6b40be346a7194d34d"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/nuxt/nuxt"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/releases/tag/v3.21.10"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nuxt/nuxt/releases/tag/v4.5.1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-178", "CWE-863" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-05T21:05:18Z",
    "nvd_published_at" : null
  }
}