{"id":"GHSA-p6jq-8vc4-79f6","summary":"Nuxt has Client-Side Path Traversal in Nuxt Island Payload Revival","details":"### Summary\n\nA client-side path traversal vulnerability in Nuxt's Island payload revival mechanism allowed attackers to manipulate client-side requests to different endpoints within the same application domain when specific prerendering conditions are met.\n\n### Technical Details\n\nThe vulnerability occurs in the client-side payload revival process (revive-payload.client.ts) where Nuxt Islands are automatically fetched when encountering serialized `__nuxt_island` objects. The issue affects the following flow:\n\n1. During prerendering, if an API endpoint returns user-controlled data containing a crafted `__nuxt_island` object\n2. This data gets serialized with `devalue.stringify` and stored in the prerendered page\n3. When a client navigates to the prerendered page, `devalue.parse` deserializes the payload\n4. The Island reviver attempts to fetch `/__nuxt_island/${key}.json` where `key` could contain path traversal sequences\n\n### Prerequisites for Exploitation\n\nThis vulnerability requires **all** of the following conditions:\n\n1. **Prerendered pages**: The application must use Nuxt's prerendering feature (`nitro.prerender`)\n2. **Attacker-controlled API responses**: The attacker must be able to control the response content of an API endpoint that is called during prerendering via `useFetch`, `useAsyncData`, or similar composables\n3. **Client-side navigation**: A user must navigate to the prerendered page (not during initial SSR hydration)\n\n### Attack Scenario\n\n```javascript\n// Malicious API response during prerendering\n{\n  \"__nuxt_island\": {\n    \"key\": \"../../../../internal/service\",\n    \"params\": { \"action\": \"probe\" }\n  }\n}\n```\n\nThis could cause the client to make requests to `/__nuxt_island/../../../../internal/service.json` if path traversal is not properly handled by the server.\n\n### Impact Assessment\n\n- **Limited Impact**: The vulnerability has a low severity due to the highly specific prerequisites\n- **No Direct Data Exfiltration**: The vulnerability does not directly expose sensitive data\n- **Client-Side Only**: Requests originate from the client, not the server\n\n### Mitigation\n\n**Action Required:**\n- Update to Nuxt 3.19.0+ or 4.1.0+ immediately\n- Review any prerendered pages that fetch external or user-controlled data\n\n**Temporary Workarounds** (if immediate update is not possible):\n1. Disable prerendering for pages that fetch user-controlled data\n2. Implement strict input validation on API endpoints used during prerendering\n3. Use allowlists for API response structures during prerendering\n\n### Fix Details\n\n[The fix](https://github.com/nuxt/nuxt/commit/2566d2046bccb158d98fb13e42ce4b2c33fb2595) implemented validation for Island keys in `revive-payload.server.ts`:\n- Island keys must match the pattern `/^[a-z][a-z\\d-]*_[a-z\\d]+$/i`\n- Maximum length of 100 characters\n- Prevents path traversal and special characters","aliases":["CVE-2025-59414"],"modified":"2025-09-18T13:04:21Z","published":"2025-09-17T20:42:28Z","database_specific":{"github_reviewed_at":"2025-09-17T20:42:28Z","nvd_published_at":"2025-09-17T19:15:47Z","cwe_ids":["CWE-22"],"severity":"LOW","github_reviewed":true},"references":[{"type":"WEB","url":"https://github.com/nuxt/nuxt/security/advisories/GHSA-p6jq-8vc4-79f6"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-59414"},{"type":"WEB","url":"https://github.com/nuxt/nuxt/commit/2566d2046bccb158d98fb13e42ce4b2c33fb2595"},{"type":"PACKAGE","url":"https://github.com/nuxt/nuxt"}],"affected":[{"package":{"name":"nuxt","ecosystem":"npm","purl":"pkg:npm/nuxt"},"ranges":[{"type":"SEMVER","events":[{"introduced":"3.6.0"},{"fixed":"3.19.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/09/GHSA-p6jq-8vc4-79f6/GHSA-p6jq-8vc4-79f6.json"}},{"package":{"name":"nuxt","ecosystem":"npm","purl":"pkg:npm/nuxt"},"ranges":[{"type":"SEMVER","events":[{"introduced":"4.0.0"},{"fixed":"4.1.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/09/GHSA-p6jq-8vc4-79f6/GHSA-p6jq-8vc4-79f6.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N"}]}