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Response snapshot Oct 31, 2026, 01:26 UTC

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VulnerabilityCVE-2026-119201

Nuxt dev server exposes generated appSecret through Vite file serving

When no appSecret is configured (via NUXT_APP_SECRET, NITRO_APP_SECRET or runtimeConfig.appSecret), nuxt dev generates a development secret and stores it in /app-secret (by default .nuxt/app-secret). The build directory is inside the directories that Nuxt passes to Vite's server.fs.

At a glance

Exploited
Not known
Severity
4.8 Medium (CVSS 3.1)
Chance of exploitation
Not estimated
Sources
1 source

What to do

GitHub lists first patched versions: @nuxt/vite-builder: 4.6.3. Confirm the affected range and upgrade guidance in the exact advisory.

Read GitHub-reviewed advisory GHSA-3xf4-9g3c-4h4w (opens a new tab)

What happened

Impact

When no appSecret is configured (via NUXT_APP_SECRET, NITRO_APP_SECRET or runtimeConfig.appSecret), nuxt dev generates a development secret and stores it in /app-secret (by default .nuxt/app-secret). The build directory is inside the directories that Nuxt passes to Vite's server.fs.allow, so the file can be fetched from the dev server:

curl http:// /_nuxt/@fs/ /.nuxt/app-secret

Anyone who can read it can compute every secret derived from it with deriveSecret(), including the default password used by useSession, and so can forge session cookies accepted by that dev server.

Continue reading

Exploitation requires direct HTTP access to the dev server. nuxt dev listens on localhost by default, so this mainly affects dev servers that are exposed to a network (for example with --host, a published container port or a tunnel). A malicious website cannot read the file through a developer's browser: Vite's CORS and host checks prevent pages on other origins from reading the response.

Production builds never generate an appSecret and are not affected. Dev servers with an explicitly configured appSecret do not use the generated file.

Patches

Fixed in @nuxt/vite-builder 4.6.3, which nuxt 4.6.3 depends on. The dev server now adds app-secret to Vite's server.fs.deny, keeping Vite's default deny list.

Workarounds

Set NUXT_APP_SECRET in .env to a random value of at least 32 characters (for example the output of openssl rand -base64 32), or avoid exposing the dev server to untrusted networks.

If a dev server using a generated secret has been reachable by untrusted clients, delete .nuxt/app-secret (a new secret is generated on the next nuxt dev) or set NUXT_APP_SECRET. Either invalidates existing dev sessions.

Affected package ranges reported by GitHub: @nuxt/vite-builder: >= 4.6.0, < 4.6.3

Scores and how they were measured

CVSS base severity

4.8

Version 3.1As of

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

Not available

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    GitHub-reviewed advisory GHSA-3xf4-9g3c-4h4w (opens a new tab)

    The public advisory supplies the description, affected package/version ranges, and any listed CVSS metric. GitHub review is not local review.

    Published Checked

  2. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-3xf4-9g3c-4h4w, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 30). Nuxt dev server exposes generated appSecret through Vite file serving (CVE-2026-119201). https://kevwire.com/record/CVE-2026-119201

MLA

"Nuxt dev server exposes generated appSecret through Vite file serving (CVE-2026-119201)." KEVWire, 30 Oct. 2026, kevwire.com/record/CVE-2026-119201.

Chicago

KEVWire. "Nuxt dev server exposes generated appSecret through Vite file serving (CVE-2026-119201)." Last modified October 30, 2026. https://kevwire.com/record/CVE-2026-119201.

Evidence summary (plain text)

Nuxt dev server exposes generated appSecret through Vite file serving (Oct 30, 2026).
When no appSecret is configured (via NUXT_APP_SECRET, NITRO_APP_SECRET or runtimeConfig.appSecret), nuxt dev generates a development secret and stores it in  /app-secret (by default .nuxt/app-secret). The build directory is inside the directories that Nuxt passes to Vite's server.fs.allow, so the file can be fetched from the dev server:

Anyone who can read it can compute every secret derived from it with deriveSecret(), including the default password used by useSession, and so can forge session cookies accepted by that dev server.

Exploitation requires direct HTTP access to the dev server.
CVSS 4.8 (version 3.1; evidence as of Oct 30, 2026; https://github.com/advisories/GHSA-3xf4-9g3c-4h4w).
Sources:
GitHub-reviewed advisory GHSA-3xf4-9g3c-4h4w: https://github.com/advisories/GHSA-3xf4-9g3c-4h4w
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc
Record ID: CVE-2026-119201.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 31, 2026, 00:50 UTC. Ingestion is not an independent editorial investigation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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