Vulnerability-Lookup

GHSA-3XF4-9G3C-4H4W

Vulnerability from github – Published: 2026-10-30 23:01 – Updated: 2026-10-30 23:01

Summary

Nuxt dev server exposes generated appSecret through Vite file serving

Details

Impact

When no appSecret is configured (via NUXT_APP_SECRET, NITRO_APP_SECRET or runtimeConfig.appSecret), nuxt dev generates a development secret and stores it in <buildDir>/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:

curl http://<dev-server>/_nuxt/@fs/<absolute-path-to-project>/.nuxt/app-secret

Anyone 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.

Exploitation 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.

Production builds never generate an appSecret and are not affected. Dev servers with an explicitly configured appSecret do not use the generated file.

Patches

Fixed 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.

Workarounds

Set 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.

If 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.

Severity

4.8 (Medium)


                  
                    CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

Show details on source website

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@nuxt/vite-builder"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.6.0"
            },
            {
              "fixed": "4.6.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-119201"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-552"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-30T23:01:12Z",
    "nvd_published_at": "2026-10-29T21:17:19Z",
    "severity": "MODERATE"
  },
  "details": "### 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\u0027s `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\u0027s browser: Vite\u0027s 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\u0027s `server.fs.deny`, keeping Vite\u0027s 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.",
  "id": "GHSA-3xf4-9g3c-4h4w",
  "modified": "2026-10-30T23:01:12Z",
  "published": "2026-10-30T23:01:12Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/nuxt/nuxt/security/advisories/GHSA-3xf4-9g3c-4h4w"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-119201"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nuxt/nuxt/commit/2981290f36d9c5412c022758f3d89ba21a845308"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nuxt/nuxt/commit/545004cc350be7003dea4116ce6206d6f980b1fd"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/nuxt/nuxt"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nuxt/nuxt/releases/tag/v4.6.3"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Nuxt dev server exposes generated appSecret through Vite file serving"
}

CVE-2026-119201 (GCVE-0-2026-119201)

Vulnerability from cvelistv5 – Published: 2026-10-29 20:21 – Updated: 2026-10-30 16:08

Title

Nuxt dev server exposes generated appSecret through Vite file serving

Summary

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 <buildDir>/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

4.8 (Medium)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-30 15:20 UTC

CWE

CWE-552 - Files or Directories Accessible to External Parties

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 8083 records in the last 180 days details

References

4 references

URL	Tags
https://github.com/nuxt/nuxt/security/advisories/…	x_refsource_CONFIRM
https://github.com/nuxt/nuxt/commit/2981290f36d9c…	x_refsource_MISC
https://github.com/nuxt/nuxt/commit/545004cc350be…	x_refsource_MISC
https://github.com/nuxt/nuxt/releases/tag/v4.6.3	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
nuxt	nuxt	Affected: >= 4.6.0, < 4.6.3

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-119201",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-30T15:20:40.211444Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-30T16:08:10.079Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "nuxt",
          "vendor": "nuxt",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 4.6.0, \u003c 4.6.3"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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\u0027s 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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 4.8,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-552",
              "description": "CWE-552: Files or Directories Accessible to External Parties",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-29T20:21:27.895Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/nuxt/nuxt/security/advisories/GHSA-3xf4-9g3c-4h4w",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/nuxt/nuxt/security/advisories/GHSA-3xf4-9g3c-4h4w"
        },
        {
          "name": "https://github.com/nuxt/nuxt/commit/2981290f36d9c5412c022758f3d89ba21a845308",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/nuxt/nuxt/commit/2981290f36d9c5412c022758f3d89ba21a845308"
        },
        {
          "name": "https://github.com/nuxt/nuxt/commit/545004cc350be7003dea4116ce6206d6f980b1fd",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/nuxt/nuxt/commit/545004cc350be7003dea4116ce6206d6f980b1fd"
        },
        {
          "name": "https://github.com/nuxt/nuxt/releases/tag/v4.6.3",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/nuxt/nuxt/releases/tag/v4.6.3"
        }
      ],
      "source": {
        "advisory": "GHSA-3xf4-9g3c-4h4w",
        "discovery": "UNKNOWN"
      },
      "title": "Nuxt dev server exposes generated appSecret through Vite file serving"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-119201",
    "datePublished": "2026-10-29T20:21:27.895Z",
    "dateReserved": "2026-10-29T16:04:48.728Z",
    "dateUpdated": "2026-10-30T16:08:10.079Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

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