{"id":"GHSA-c9cv-mq2m-ppp3","summary":"Nuxt: URL-handling weaknesses in `navigateTo` and `reloadNuxtApp`: SSR open redirect, client-side script execution via the `open` option, and protocol-relative bypass in `reloadNuxtApp`","details":"### Summary\n\nThree weaknesses in Nuxt's client-navigation URL handling, all reachable\nfrom documented public APIs (`navigateTo` and `reloadNuxtApp`):\n\n1. **(CVE-2026-56326) SSR open redirect in `navigateTo` via path-normalisation bypass.** \n   `navigateTo` decided whether a target was external by inspecting the raw\n   input with `hasProtocol(..., { acceptRelative: true })`. Inputs such as\n   `/..//evil.com`, `/.//evil.com`, `/%2e%2e//evil.com`, or\n   `/app/..//evil.com` slipped past that check because they start with\n   `/`, but WHATWG URL parsing then normalised them to the\n   protocol-relative pathname `//evil.com`. The normalised value was\n   written to the `Location` response header and into the\n   `\u003cmeta http-equiv=\"refresh\"\u003e` body of the SSR redirect page, so a\n   victim's browser would resolve the redirect cross-origin to the\n   attacker's host.\n\n2. **(CVE-2026-56698) Client-side script execution via `navigateTo({ open: ... })`.** The\n   client-side early-open handler called `window.open(toPath, ...)` without\n   applying the `isScriptProtocol` check that gates the normal `navigateTo`\n   path. A target of `javascript:...` (or another script-capable scheme)\n   passed to `navigateTo(url, { open: { ... } })` therefore executed in the\n   application's origin instead of being rejected.\n\n3. **(CVE-2026-56697) Open redirect in `reloadNuxtApp` via protocol-relative bypass.**\n   `reloadNuxtApp({ path })` rejects script-capable protocols by parsing\n   the path with `new URL(path, window.location.href)` and checking the\n   resolved `protocol` against `isScriptProtocol`. Protocol-relative paths\n   such as `//evil.com` resolve to the current page's protocol (`https:`),\n   which passes that check; the value is then assigned to\n   `window.location.href`, which the browser treats as a cross-origin\n   redirect. This is the same protocol-relative bypass family as (1), in\n   a different sink.\n\n### Impact\n\nFor (1), the practical risk is phishing or OAuth-code theft against any\nNuxt app that forwards user-controlled input (for example a `?next=`\nquery parameter on a login route) into `navigateTo` on the server. The\nframework documents that `navigateTo` blocks external hosts unless\n`external: true` is passed, so maintainers commonly rely on it as the\nsafe path for post-login redirects.\n\nFor (2), any app that passes a user-controlled URL into\n`navigateTo(url, { open: { ... } })` was vulnerable to reflected XSS in\nthe application's first-party origin.\n\nFor (3), any app that forwards user-controlled input into\n`reloadNuxtApp({ path })` could be redirected cross-origin for phishing\nor OAuth-code theft, even on releases that already shipped the\n`isScriptProtocol` guard added by [#35115](https://github.com/nuxt/nuxt/pull/35115).\n\n### Patches\n\nFixed in `nuxt@4.4.7` and backported to `nuxt@3.21.7`. The three sinks\nare addressed by:\n\n- Path-normalisation bypass in `navigateTo`:\n  - 4.x: commit [`2cce6fb0`](https://github.com/nuxt/nuxt/commit/2cce6fb02e621196d56df92e05594e07469b5a6d)\n  - 3.x: commit [`1f2dd5e7`](https://github.com/nuxt/nuxt/commit/1f2dd5e78c77576437138e97671965573c232835)\n- `navigateTo({ open })` script-protocol guard:\n  - 4.x: [#35206](https://github.com/nuxt/nuxt/pull/35206) (commit [`3394716d`](https://github.com/nuxt/nuxt/commit/3394716d4a913cba904b028df5338f2aead50032))\n  - 3.x: commit [`62fc32ed`](https://github.com/nuxt/nuxt/commit/62fc32eddf648b00a3890141e0235d2a222b024d)\n- Protocol-relative bypass in `reloadNuxtApp`:\n  - 4.x: commit [`e447a793`](https://github.com/nuxt/nuxt/commit/e447a793c47766834f7497f8412a76cd56fd8ee1)\n  - 3.x: commit [`6497d99d`](https://github.com/nuxt/nuxt/commit/6497d99dd106254abd089f6a263d7773869a343b)\n\n### Workarounds\n\n- For (1): validate redirect targets before passing them to `navigateTo`,\n  for example reject any input where\n  `new URL(target, 'http://localhost').pathname` starts with `//`, or\n  only accept a known allow-list of paths.\n- For (2): reject any user-controlled URL whose protocol is not in an\n  allow-list (typically just `http:` and `https:`) before passing it to\n  `navigateTo({ open: ... })`.\n- For (3): same shape as (1). Reject paths starting with `//` (or where\n  `new URL(path, window.location.href).host !== window.location.host`)\n  before passing to `reloadNuxtApp({ path })`.\n\n### References\n\n- CWE-601: URL Redirection to Untrusted Site ('Open Redirect')\n- CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')\n\n### Credits\n\nReported by Anthropic / Claude as `ANT-2026-S08HN6DH` through Anthropic's\ncoordinated vulnerability disclosure programme.\n\nThe `reloadNuxtApp` protocol-relative bypass (sink 3) was independently\nreported by [@alcls01111](https://github.com/alcls01111) via GitHub's\ncoordinated disclosure flow (`GHSA-w7fp-2cfv-4837`), closed as a\nduplicate of this advisory.","aliases":["CVE-2026-56326","CVE-2026-56697","CVE-2026-56698"],"modified":"2026-09-18T21:00:05.238411523Z","published":"2026-06-16T13:47:52Z","database_specific":{"nvd_published_at":"2026-06-22T22:16:52Z","cwe_ids":["CWE-79","CWE-601"],"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2026-06-16T13:47:52Z"},"references":[{"type":"WEB","url":"https://github.com/nuxt/nuxt/security/advisories/GHSA-c9cv-mq2m-ppp3"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-56326"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-56697"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-56698"},{"type":"WEB","url":"https://github.com/nuxt/nuxt/pull/35115"},{"type":"WEB","url":"https://github.com/nuxt/nuxt/pull/35206"},{"type":"WEB","url":"https://github.com/nuxt/nuxt/commit/1f2dd5e78c77576437138e97671965573c232835"},{"type":"WEB","url":"https://github.com/nuxt/nuxt/commit/2cce6fb02e621196d56df92e05594e07469b5a6d"},{"type":"WEB","url":"https://github.com/nuxt/nuxt/commit/3394716d4a913cba904b028df5338f2aead50032"},{"type":"WEB","url":"https://github.com/nuxt/nuxt/commit/62fc32eddf648b00a3890141e0235d2a222b024d"},{"type":"WEB","url":"https://github.com/nuxt/nuxt/commit/6497d99dd106254abd089f6a263d7773869a343b"},{"type":"WEB","url":"https://github.com/nuxt/nuxt/commit/e447a793c47766834f7497f8412a76cd56fd8ee1"},{"type":"PACKAGE","url":"https://github.com/nuxt/nuxt"},{"type":"WEB","url":"https://www.vulncheck.com/advisories/nuxt-cross-site-scripting-via-navigateto-open-option"},{"type":"WEB","url":"https://www.vulncheck.com/advisories/nuxt-open-redirect-via-protocol-relative-paths-in-reloadnuxtapp"},{"type":"WEB","url":"https://www.vulncheck.com/advisories/nuxt-server-side-open-redirect-via-path-normalization-bypass-in-navigateto"}],"affected":[{"package":{"name":"nuxt","ecosystem":"npm","purl":"pkg:npm/nuxt"},"ranges":[{"type":"SEMVER","events":[{"introduced":"4.0.0"},{"fixed":"4.4.7"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-c9cv-mq2m-ppp3/GHSA-c9cv-mq2m-ppp3.json"}},{"package":{"name":"nuxt","ecosystem":"npm","purl":"pkg:npm/nuxt"},"ranges":[{"type":"SEMVER","events":[{"introduced":"3.5.0"},{"fixed":"3.21.7"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-c9cv-mq2m-ppp3/GHSA-c9cv-mq2m-ppp3.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:L/SA:N"}]}