{"id":"CVE-2026-119200","aliases":["GHSA-9v7c-q64q-vv33"],"url":"https://o3.security/vulnerability/CVE-2026-119200","summary":"Nuxt: Dot segments in the request path bypass `server/middleware` path checks and server route rules on page routes","details":"### Summary\n\nSince `4.6.0`, Nuxt resolves `.` and `..` segments in the request path, including percent-encoded forms such as `%2e`, before rendering a page. Nitro's routing, Nitro's route rules and `server/middleware` see the path with those segments still in place. A request for `/%2e/admin` therefore renders the page at `/admin`, while server-side checks keyed on `/admin` do not apply.\n\n### Impact\n\nAn unauthenticated attacker can bypass server-side controls that match on the request path of a page route.\n\n`server/middleware` that checks `event.path` (or `event.node.req.url`) is skipped:\n\n```ts\nexport default defineEventHandler((event) => {\n  if (event.path.startsWith('/admin') && !isAuthenticated(event)) {\n    throw createError({ statusCode: 401 })\n  }\n})\n```\n\nWith this middleware, `/admin` returns 401, but `/%2e/admin`, `/.%2e/admin` and `/x/%2e%2e/admin` reach the middleware with `event.path` set to `/./admin`, `/../admin` and `/x/../admin`, and render `app/pages/admin.vue` along with the data it fetches during server rendering.\n\nServer-side `redirect` and `headers` route rules are skipped in the same way, so `'/admin/**': { redirect: '/login' }` does not redirect `/%2e/admin/secret`, and per-route security headers such as `Content-Security-Policy` are not sent.\n\nNot affected:\n\n- API handlers in `server/api` and `server/routes`. Nitro's router does not resolve dot segments, so these requests do not reach the handler.\n- `appMiddleware` route rules and middleware declared with `definePageMeta`, which are matched against the resolved route.\n- Nuxt `3.x` and `4.0.0` to `4.5.x`, which pass the path to the page router unchanged, so these requests 404.\n\nBrowsers resolve dot segments before sending a request, so exploitation requires a client that sends the path as written.\n\n### Patches\n\nFixed in `nuxt@4.6.3` and `@nuxt/nitro-server@4.6.3`. A page request whose path contains `.` or `..` segments now receives a 404 instead of rendering the page the path resolves to, and route-rule keys and lookup paths have their dot segments resolved, including percent-encoded spellings, before they are compared.\n\n### Workarounds\n\nReject dot segments in a server middleware that runs before your other middleware (middleware runs in file name order):\n\n```ts\n// server/middleware/0.dot-segments.ts\nexport default defineEventHandler((event) => {\n  if (/(?:^|\\/)\\.{1,2}(?:\\/|$)/.test(event.path.split('?')[0])) {\n    throw createError({ statusCode: 404 })\n  }\n})\n```\n\nChecking `getRequestURL(event).pathname` instead of `event.path` is not a sufficient workaround: it resolves dot segments, but keeps percent-encoding such as `%61` that the page router decodes. Path checks in server middleware should also account for the page router matching paths case-insensitively unless `router.options.sensitive` is set.\n\nA reverse proxy or CDN that normalises the request path before forwarding it also removes the mismatch.\n\n### Credits\n\nThanks to @vinzabe, @nikhilagrawalsf (Nikhil Agrawal, Mettle Labs), @0xjunwei and @kq5y, who reported this issue independently.","published":"2026-10-29T20:17:08.837Z","modified":"2026-10-31T02:47:37.160907432Z","cvss":{"score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"npm","name":"nuxt","fixedVersion":"4.6.3"},{"ecosystem":"npm","name":"@nuxt/nitro-server","fixedVersion":"4.6.3"}],"fix":{"url":"https://github.com/nuxt/nuxt/commit/45463f8b58487e387149ebfb704d6a0834b3a450","label":"nuxt/nuxt@45463f8"},"references":[{"type":"WEB","url":"https://github.com/nuxt/nuxt/releases/tag/v4.6.3"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/119xxx/CVE-2026-119200.json"},{"type":"ADVISORY","url":"https://github.com/nuxt/nuxt/security/advisories/GHSA-9v7c-q64q-vv33"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-119200"},{"type":"FIX","url":"https://github.com/nuxt/nuxt/commit/45463f8b58487e387149ebfb704d6a0834b3a450"},{"type":"PACKAGE","url":"https://github.com/nuxt/nuxt"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-31T02:47:37.160907432Z"}}