npm · nuxt
Nuxt route rules silently dropped for mixed-case paths, bypassing appMiddleware auth gates (incomplete fix for CVE-2026-53721)
Nuxt 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.
vue-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.
Fixed 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.
Scope 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).
If you cannot upgrade immediately, any one of:
routeRules (and name your page files) in lowercase, so the keys already match the folded lookup path.router: { options: { sensitive: true } } so routing and route-rule matching are both case-sensitive and exact (requests must then use the exact casing).Is your project exposed to this? Stateward checks every dependency on every pull request and flags it only if your code actually reaches it.
Check my repoSources: CISA KEV (public domain), OSV.dev & GitHub Advisory Database (CC-BY-4.0), FIRST EPSS, NVD/CWE (public domain). Served live from the Stateward advisory database.