Nuxt dev server exposes generated appSecret through Vite file serving
Impact
Nuxt dev server exposes a generated appSecret through Vite file serving when no appSecret is configured, affecting versions 4.6.0 to 4.6.3. Exploitation requires direct HTTP access to the dev server. A malicious actor can compute secrets derived from the appSecret, including the default password used by useSession.
Summarized by @cf/meta/llama-3.3-70b-instruct-fp8-fast. Verify details against the original sources.Exploitation requires direct HTTP access to the dev server.
Affected packages
Start with the recorded fix for your release branch. Check your installed version and test compatibility before upgrading. Fixing this advisory does not rule out other vulnerabilities in the release.
| Affected range | Recorded fix |
|---|---|
| From 4.6.0 before 4.6.3Semantic versions | 4.6.3 |
Version evidence: OSV · GHSA-3xf4-9g3c-4h4w
View original version evidence (0 explicit versions)
Affected products
Vendor version evidence. Product records are separate from automatic dependency matching.
nuxt · GitHub_M
nuxt
1 range
nuxt · GitHub_M
nuxt
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affected
>= 4.6.0, < 4.6.3
Other versions: unknown
Original source description
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 <buildDir>/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://<dev-server>/_nuxt/@fs/<absolute-path-to-project>/.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.
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.
Inside the record
Evidence available
Describes the evidence in this view, not whether the product is safe.
Original records
CVE-2026-119201View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.
cve.new JSON →Underlying weaknesses
The source’s classification of what caused the vulnerability.
Contributing organizations · 2
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Additional data publisher
What changed
Follow changes- CVE · CVE-2026-119201
Observed 2026-10-30T17:29:32.709Z · upstream updated 2026-10-30T16:08:10.079Z
Prioritization updated
before
[]
after
[ { "source": "CISA-ADP", "type": "SSVC", "role": "CISA Coordinator", "timestamp": "2026-10-30T15:20:40.211444Z", "decisions": [ { "name": "Exploitation", "value": "none" }, { "name": "Automatable", "value": "no" }, { "name": "Technical Impact", "value": "partial" } ] } ]
Large field values are marked as truncated previews. Original source snapshots remain retained.
Showing up to 50 most recent observed changes.