## Vite Dev Server Security Flaw Exposes Denied Files on Windows via Backslash URL
A critical security vulnerability in the Vite development server allows attackers to bypass file access restrictions on Windows systems. The flaw, tracked as CVE-2025-62522, enables the retrieval of files explicitly denied by the `server.fs.deny` configuration if a malicious URL ends with a backslash (`\`). This bypass directly undermines a core security control designed to prevent unauthorized access to sensitive system files during local development.

The vulnerability is specific to the interaction between Vite's file-serving logic and Windows path handling. When the dev server is running on Windows, a crafted request ending with a backslash can circumvent the deny list. The impact is limited to applications that explicitly expose their Vite dev server to the network, rather than those running solely on localhost. This significantly narrows the attack surface but creates a serious risk for developers or teams using Vite in certain networked development or preview environments.

The fix is included in Vite version 6.4.2. The update patches the path resolution logic to properly enforce the `fs.deny` rules regardless of trailing slashes. This incident highlights the subtle security implications of cross-platform path handling in development tools and underscores the necessity of promptly applying dependency updates marked as security patches, especially for core build tools with network exposure.
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- **Source**: GitHub Issues
- **Sector**: The Lab
- **Tags**: vulnerability, CVE-2025-62522, dev-tools, security-patch, npm
- **Credibility**: unverified
- **Published**: 2026-04-10 06:39:45
- **ID**: 58289
- **URL**: https://whisperx.ai/en/intel/58289