GHSA-fx6j-w5w5-h468: Nuxt: Reflected XSS in `navigateTo()` external redirect
Summary
navigateTo() with external: true generates a server-side HTML redirect body containing a <meta http-equiv="refresh"> tag. The destination URL is only sanitized by replacing " with %22, leaving <, >, &, and ' unencoded. An attacker who can influence the URL passed to navigateTo(url, { external: true }) can break out of the content="…" attribute and inject arbitrary HTML/JavaScript that executes under the application's origin.
This is a different root cause from CVE-2024-34343 (GHSA-vf6r-87q4-2vjf), which addressed javascript: protocol bypass. The issue here is triggered by any valid URL containing >.
Impact
Applications that pass user-controlled input to navigateTo(url, { external: true }) — typically via a ?next= / ?redirect= query parameter used for post-login or "return to" flows — are vulnerable to reflected cross-site scripting. The injected script runs in the context of the application's origin during the server-rendered redirect response, before the meta-refresh fires.
Details
In packages/nuxt/src/app/composables/router.ts, the SSR redirect path builds an HTML response body with only " percent-encoded in the destination URL:
const encodedLoc = location.replace(/"/g, '%22')
nuxtApp.ssrContext!['~renderResponse'] = {
status: sanitizeStatusCode(options?.redirectCode || 302, 302),
body: <!DOCTYPE html><html><head><meta http-equiv="refresh" content="0; url=${encodedLoc}"></head></html>,
headers: { location: encodeURL(location, isExternalHost) },
}
The Location header is normalised through encodeURL() (which uses the URL constructor and correctly percent-encodes attribute-significant characters). The HTML body uses a narrower sanitiser. That mismatch is the root cause.
Proof of concept
Global middleware that forwards a query parameter to navigateTo:
// middleware/redirect.global.ts
export default defineNuxtRouteMiddleware((to) => {
const next = to.query.next as string | undefined
if (next) {
return navigateTo(next, { external: true })
}
})
Request:
Details
Original advisory: https://github.com/advisories/GHSA-fx6j-w5w5-h468
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-456690.16% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 6% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-45669 | coverage & exploitation status | NVD · CVE.org |
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