Nuxt dev server exposes private runtime config through the Nitro dev bundle

published 2026-10-29 10 d ago modified 2026-10-30 9 d ago also GHSA-648h-gw55-m2g7 , EUVD-2026-113370

cvss: 5.9; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 28%
public exploits: 0; none known

Nuxt is an open-source web development framework for Vue.js. From 3.0.0 until 4.6.3, the Nuxt development server can expose the Nitro 2 development bundle at <buildDir>/dev/index.mjs through Vite file serving when the server is reachable over HTTP. Nitro inlines private runtimeConfig values resolved at build time into that bundle, including secrets configured in nuxt.config, and Nuxt 4.6.0 and later also inline the generated development appSecret. The default localhost binding limits remote exposure, production builds and Nitro 3 are not affected, and runtime configuration supplied only through NUXT_* environment variables at server startup is not inlined. This issue is fixed in version 4.6.3.

Patch / fix

fixed in 1 links 2

npm @nuxt/vite-builder 4.6.3

github.com/nuxt/nuxt@12b58f9 commit
github.com/nuxt/nuxt/releases/tag/v4.6.3 release

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 10 d ago (2026-10-29)

Exploit prediction

0.35% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.9	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
GitHub	3.1	5.9	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
npm	@nuxt/vite-builder	>=3.0.0, <4.6.3	4.6.3

Affected products

nuxt nuxt

Classification

Weakness

CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
CWE-538 Insertion of Sensitive Information into Externally-Accessible File or Directory
CWE-552 Files or Directories Accessible to External Parties

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary