CVE-2026-45670: Nuxt: Dev server exposes built source over LAN to malicious sites (incomplete fix for GHSA-4gf7-ff8x-hq99)

Severity: medium (CVSS 5.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-06-12 · updated 2026-06-17
Weakness: CWE-749

Description

Nuxt is an open-source web development framework for Vue.js. In @nuxt/rspack-builder and @nuxt/webpack-builder versions 3.15.4 to before 3.21.6, and 4.0.0-alpha.1 to before 4.4.6, there is an incomplete fix for GHSA-4gf7-ff8x-hq99. Source code may 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 3.21.6 and 4.4.6.

Affected products

Nuxt/Rspack-Builder: from 3.12.2 before 3.21.5; from 4.0.0 before 4.4.5 — fixed in 3.21.5, 4.4.5
Nuxt/Webpack-Builder: from 3.0.0 before 3.21.5; from 4.0.0 before 4.4.5 — fixed in 3.21.5, 4.4.5

How to fix

Upgrade to a fixed version: Nuxt/Rspack-Builder 3.21.5, 4.4.5; Nuxt/Webpack-Builder 3.21.5, 4.4.5. Check the vendor advisory for mitigations.

References

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