---
id: "CVE-2026-114063"
kind: "vulnerability"
aliases: ["CVE-2026-114063"]
title: "SvelteKit on Windows: preview server path traversal exposes server files"
severity: "high"
cvss: 8.7
epss: 0.00405
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["package", "sveltekit", "vite", "windows"]
not_affected_if: ["linux-or-macos-only", "no-preview-server-exposed", "static-hosting"]
published_at: "2026-10-21T01:17:29+00:00"
first_seen_at: "2026-10-23T21:57:27+00:00"
updated_at: "2026-10-24T13:15:55+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-114063", "first_seen_at": "2026-10-23T21:57:27+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-114063", "first_seen_at": "2026-10-24T13:15:55+00:00"}]
---

# SvelteKit on Windows: preview server path traversal exposes server files

SvelteKit's vite preview server on Windows fails to block path traversal, so anyone who can reach it can read files outside the prerendered output directory. Readable source code, configuration, or credentials on the server can be exposed without logging in.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

Run 'npm ls @sveltejs/kit' to find versions 2.10.0 through 2.x; check whether 'vite preview' runs on a Windows host reachable from a network or tunnel.

## Fix

Upgrade @sveltejs/kit to 3.0.0 or later; do not expose 'vite preview' to networks, and rotate any secrets the preview process could read if it was reachable.

## Timeline

- 2026-10-23T21:57:27+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-114063
- 2026-10-24T13:15:55+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-114063

## From the sources

SvelteKit (@sveltejs/kit) from 2.10.0 before 3.0.0 contains a path traversal vulnerability in the vite preview server on Windows that allows unauthenticated attackers to read files outside the prerendered output directory. Attackers who can reach the preview server through network access or a tunnel can send crafted requests to expose source code, configuration, or credentials readable by the server process.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_