EUVD-2026-326849

fkie_cve-2026-49993

Nuxt is an open-source web development framework for Vue.js. In @nuxt/rspack-builder and @nuxt/webpack-builder from versions 3.15.4 to before 3.21.7 and 4.0.0 to before 4.4.7, there is an incomplete fix for GHSA-6m52-m754-pw2g. Source code may still be stolen during dev when using the webpack / rspack builder if the dev server is bound to a non-loopback address (e.g. nuxt dev --host) and the developer opens a malicious site on the same network. This issue has been patched in versions 3.21.7 and 4.4.7.

GHSA-x6qj-4h56-5rj5 — @nuxt/webpack-builder and @nuxt/rspack-builder dev server same-origin check bypassed when Sec-Fetch-Site, Origin, and R…

Affected: npm: @nuxt/webpack-builder, npm: @nuxt/rspack-builder

### Summary This is an incomplete fix for [GHSA-6m52-m754-pw2g](https://github.com/nuxt/nuxt/security/advisories/GHSA-6m52-m754-pw2g). Source code may still be stolen during dev when using the webpack / rspack builder if the dev server is bound to a non-loopback address (e.g. `nuxt dev --host`) and the developer opens a malicious site on the same network.

### Details The fix for [GHSA-6m52-m754-pw2g](https://github.com/nuxt/nuxt/security/advisories/GHSA-6m52-m754-pw2g) added an `Origin` / `Referer` fallback to the dev-middleware same-origin check, with a `return true` branch when neither header is present so that non-browser clients (curl, the HMR client, address-bar navigation) keep working.

That fallback is bypassed when a cross-origin attacker request reaches the dev server with all three signal headers absent:

- `Sec-Fetch-Site` is [not sent by browsers to non-potentially-trustworthy destinations](https://w3c.github.io/webappsec-fetch-metadata/#sec-fetch-site-header) (HTTP on a non-loopback address). - `Origin` is not sent on non-CORS subresource fetches (a bare `<script>` with no `crossorigin`). - `Referer` can be suppressed by the attacker page with `<meta name="referrer" content="no-referrer">` or `referrerpolicy="no-referrer"` on the `<script>` element.

A classic `<script src="http://VICTIM_LAN_IP:3000/_nuxt/app.js" referrerpolicy="no-referrer">` from a non-trustworthy attacker origin produces exactly that header set, the request is allowed, and the attacker page…

Most recent entries from all

EUVD-2026-326849

fkie_cve-2026-49993

GHSA-x6qj-4h56-5rj5 — @nuxt/webpack-builder and @nuxt/rspack-builder dev server same-origin check bypassed when Sec-Fetch-Site, Origin, and R…