{"id":"CVE-2026-119201","aliases":["EUVD-2026-113372","GHSA-3xf4-9g3c-4h4w"],"status":"published","title":"Nuxt dev server exposes generated appSecret through Vite file serving","description":"Nuxt is an open-source web development framework for Vue.js. From 4.6.0 until 4.6.3, nuxt dev stores a generated appSecret in \u003cbuildDir\u003e/app-secret, by default .nuxt/app-secret, within a directory allowed by Vite's server.fs configuration. A client with direct HTTP access to an exposed development server can fetch the file, use deriveSecret() to compute derived secrets such as the default useSession password, and forge session cookies accepted by that development server. The default localhost binding limits remote exposure, cross-origin browser reads are blocked, production builds and development servers with an explicitly configured appSecret are not affected. This issue is fixed in version 4.6.3.","severity":{"version":"3.1","score":4.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00205,"percentile":0.10493,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-552"],"published":"2026-10-29T20:21:27Z","modified":"2026-11-01T02:30:35Z","fixes":[{"ecosystem":"npm","package":"@nuxt/vite-builder","fixed_in":["4.6.3"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"@nuxt/vite-builder","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.6.0"},{"fixed":"4.6.3"}]}]},{"source":"osv","ecosystem":"npm","package":"@nuxt/vite-builder","ranges":[{"type":"SEMVER","events":[{"introduced":"4.6.0"},{"fixed":"4.6.3"}]}]}],"products":[{"vendor":"@clerk","product":"nuxt"},{"vendor":"nuxt","product":"nuxt"}],"references":[{"url":"https://github.com/nuxt/nuxt/security/advisories/GHSA-3xf4-9g3c-4h4w","tags":["x_refsource_CONFIRM","advisory","web"]},{"url":"https://github.com/nuxt/nuxt/commit/2981290f36d9c5412c022758f3d89ba21a845308","tags":["x_refsource_MISC","fix","web"]},{"url":"https://github.com/nuxt/nuxt/commit/545004cc350be7003dea4116ce6206d6f980b1fd","tags":["x_refsource_MISC","fix","web"]},{"url":"https://github.com/nuxt/nuxt/releases/tag/v4.6.3","tags":["x_refsource_MISC","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-119201","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-3xf4-9g3c-4h4w"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/119xxx/CVE-2026-119201.json","tags":["advisory"]},{"url":"https://github.com/nuxt/nuxt","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-119201","title":"Nuxt dev server exposes generated appSecret through Vite file serving","description":"Nuxt is an open-source web development framework for Vue.js. From 4.6.0 until 4.6.3, nuxt dev stores a generated appSecret in \u003cbuildDir\u003e/app-secret, by default .nuxt/app-secret, within a directory allowed by Vite's server.fs configuration. A client with direct HTTP access to an exposed development server can fetch the file, use deriveSecret() to compute derived secrets such as the default useSession password, and forge session cookies accepted by that development server. The default localhost binding limits remote exposure, cross-origin browser reads are blocked, production builds and development servers with an explicitly configured appSecret are not affected. This issue is fixed in version 4.6.3.","status":"published","published":"2026-10-29T20:21:27.895Z","modified":"2026-10-30T16:08:10.079Z","cvss":[{"version":"3.1","score":4.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-552"],"updated_at":"2026-11-02T14:20:10.143031Z"}],"euvd":[{"id":"EUVD-2026-113372","description":"Nuxt is an open-source web development framework for Vue.js. From 4.6.0 until 4.6.3, nuxt dev stores a generated appSecret in \u003cbuildDir\u003e/app-secret, by default .nuxt/app-secret, within a directory allowed by Vite's server.fs configuration. A client with direct HTTP access to an exposed development server can fetch the file, use deriveSecret() to compute derived secrets such as the default useSession password, and forge session cookies accepted by that development server. The default localhost binding limits remote exposure, cross-origin browser reads are blocked, production builds and development servers with an explicitly configured appSecret are not affected. This issue is fixed in version 4.6.3.","status":"published","published":"2026-10-29T20:21:27Z","modified":"2026-10-30T16:08:10Z","cvss":[{"version":"3.1","score":4.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T16:59:05.913237Z"}],"ghsa":[{"id":"GHSA-3xf4-9g3c-4h4w","title":"Nuxt dev server exposes generated appSecret through Vite file serving","description":"### Impact\n\nWhen no `appSecret` is configured (via `NUXT_APP_SECRET`, `NITRO_APP_SECRET` or `runtimeConfig.appSecret`), `nuxt dev` generates a development secret and stores it in `\u003cbuildDir\u003e/app-secret` (by default `.nuxt/app-secret`). The build directory is inside the directories that Nuxt passes to Vite's `server.fs.allow`, so the file can be fetched from the dev server:\n\n```bash\ncurl http://\u003cdev-server\u003e/_nuxt/@fs/\u003cabsolute-path-to-project\u003e/.nuxt/app-secret\n```\n\nAnyone who can read it can compute every secret derived from it with `deriveSecret()`, including the default password used by `useSession`, and so can forge session cookies accepted by that dev server.\n\nExploitation requires direct HTTP access to the dev server. `nuxt dev` listens on localhost by default, so this mainly affects dev servers that are exposed to a network (for example with `--host`, a published container port or a tunnel). A malicious website cannot read the file through a developer's browser: Vite's CORS and host checks prevent pages on other origins from reading the response.\n\nProduction builds never generate an `appSecret` and are not affected. Dev servers with an explicitly configured `appSecret` do not use the generated file.\n\n### Patches\n\nFixed in `@nuxt/vite-builder` 4.6.3, which `nuxt` 4.6.3 depends on. The dev server now adds `app-secret` to Vite's `server.fs.deny`, keeping Vite's default deny list.\n\n### Workarounds\n\nSet `NUXT_APP_SECRET` in `.env` to a random value of at least 32 characters (for example the output of `openssl rand -base64 32`), or avoid exposing the dev server to untrusted networks.\n\nIf a dev server using a generated secret has been reachable by untrusted clients, delete `.nuxt/app-secret` (a new secret is generated on the next `nuxt dev`) or set `NUXT_APP_SECRET`. Either invalidates existing dev sessions.","status":"published","published":"2026-10-30T23:01:12Z","modified":"2026-10-30T23:01:13Z","cvss":[{"version":"3.1","score":4.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-552"],"updated_at":"2026-11-02T14:41:41.028239Z"}],"nvd":[{"id":"CVE-2026-119201","description":"Nuxt is an open-source web development framework for Vue.js. From 4.6.0 until 4.6.3, nuxt dev stores a generated appSecret in \u003cbuildDir\u003e/app-secret, by default .nuxt/app-secret, within a directory allowed by Vite's server.fs configuration. A client with direct HTTP access to an exposed development server can fetch the file, use deriveSecret() to compute derived secrets such as the default useSession password, and forge session cookies accepted by that development server. The default localhost binding limits remote exposure, cross-origin browser reads are blocked, production builds and development servers with an explicitly configured appSecret are not affected. This issue is fixed in version 4.6.3.","status":"published","published":"2026-10-29T21:17:19.077Z","modified":"2026-10-30T17:18:03.88Z","cvss":[{"version":"3.1","score":4.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-552"],"updated_at":"2026-11-02T14:13:04.940026Z"}],"osv":[{"id":"CVE-2026-119201","title":"Nuxt dev server exposes generated appSecret through Vite file serving","description":"Nuxt is an open-source web development framework for Vue.js. From 4.6.0 until 4.6.3, nuxt dev stores a generated appSecret in \u003cbuildDir\u003e/app-secret, by default .nuxt/app-secret, within a directory allowed by Vite's server.fs configuration. A client with direct HTTP access to an exposed development server can fetch the file, use deriveSecret() to compute derived secrets such as the default useSession password, and forge session cookies accepted by that development server. The default localhost binding limits remote exposure, cross-origin browser reads are blocked, production builds and development servers with an explicitly configured appSecret are not affected. This issue is fixed in version 4.6.3.","status":"published","published":"2026-10-29T20:21:27.895Z","modified":"2026-11-03T02:46:22.342701223Z","cvss":[{"version":"3.1","score":4.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-552"],"updated_at":"2026-11-03T03:05:43.703218Z"},{"id":"GHSA-3xf4-9g3c-4h4w","title":"Nuxt dev server exposes generated appSecret through Vite file serving","description":"### Impact\n\nWhen no `appSecret` is configured (via `NUXT_APP_SECRET`, `NITRO_APP_SECRET` or `runtimeConfig.appSecret`), `nuxt dev` generates a development secret and stores it in `\u003cbuildDir\u003e/app-secret` (by default `.nuxt/app-secret`). The build directory is inside the directories that Nuxt passes to Vite's `server.fs.allow`, so the file can be fetched from the dev server:\n\n```bash\ncurl http://\u003cdev-server\u003e/_nuxt/@fs/\u003cabsolute-path-to-project\u003e/.nuxt/app-secret\n```\n\nAnyone who can read it can compute every secret derived from it with `deriveSecret()`, including the default password used by `useSession`, and so can forge session cookies accepted by that dev server.\n\nExploitation requires direct HTTP access to the dev server. `nuxt dev` listens on localhost by default, so this mainly affects dev servers that are exposed to a network (for example with `--host`, a published container port or a tunnel). A malicious website cannot read the file through a developer's browser: Vite's CORS and host checks prevent pages on other origins from reading the response.\n\nProduction builds never generate an `appSecret` and are not affected. Dev servers with an explicitly configured `appSecret` do not use the generated file.\n\n### Patches\n\nFixed in `@nuxt/vite-builder` 4.6.3, which `nuxt` 4.6.3 depends on. The dev server now adds `app-secret` to Vite's `server.fs.deny`, keeping Vite's default deny list.\n\n### Workarounds\n\nSet `NUXT_APP_SECRET` in `.env` to a random value of at least 32 characters (for example the output of `openssl rand -base64 32`), or avoid exposing the dev server to untrusted networks.\n\nIf a dev server using a generated secret has been reachable by untrusted clients, delete `.nuxt/app-secret` (a new secret is generated on the next `nuxt dev`) or set `NUXT_APP_SECRET`. Either invalidates existing dev sessions.","status":"published","published":"2026-10-30T23:01:12Z","modified":"2026-10-30T23:15:04.501043731Z","cvss":[{"version":"3.1","score":4.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-552"],"updated_at":"2026-11-02T15:46:36.092962Z"}]}}