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high·Product Based Web Vulnerabilities·Updated Apr 17, 2026

CVE-2026-39363 Scanner

CVE-2026-39363 Scanner - Arbitrary File Read vulnerability in Vite Dev Server

Est. Time~10 seconds
Scan TypeGroup Scan
Targetsdomain, subdomain, ipv4
CostFree
2.2k
Times Used
continuous scan runs
6k
Continuously Checked
assets under CS
0
Vulnerabilities Found
confirmed findings
References
CVECVE-2026-39363
8.2
CVSShigh
Exploitable remotely over the internet · no authentication required.

Vite is a frontend tooling framework for JavaScript. From 6.0.0 to before 6.4.2, 7.3.2, and 8.0.5, if it is possible to connect to the Vite dev server’s WebSocket without an Origin header, an attacker can invoke fetchModule via the custom WebSocket event vite:invoke and combine file://... with ?raw (or ?inline) to retrieve the contents of arbitrary files on the server as a JavaScript string (e.g., export default "..."). The access control enforced in the HTTP request path (such as server.fs.allow) is not applied to this WebSocket-based execution path. This vulnerability is fixed in 6.4.2, 7.3.2, and 8.0.5.

Attack Vector
Network
Privileges Req.
None
User Interaction
None
Affected
viteby vitejs
>= 8.0.0, < 8.0.5
vite-plusby vitejs
< 0.1.16
Red Hat Ansible Automation Platform 2.5 for RHEL 8by Red Hat
AFFECTED< *SAFE ✓≥ *
Red Hat Ansible Automation Platform 2.5 for RHEL 9by Red Hat
AFFECTED< *SAFE ✓≥ *
Updated Sep 9, 2026View on NVD →
Detail

Vite Dev Server is primarily used by developers as a frontend build tool to serve applications in a local development environment. It leverages a dev server to support fast hot module replacement and rich feature sets designed for modern JavaScript projects. Vite's extensive plugin and API system make it a popular choice among developers who require efficient and rapid development tools. The Vite community regularly updates the framework, ensuring compatibility with the latest web technologies. Although primarily used during development, it's essential for developers to be cautious when exposing Vite Dev Server externally. This server facilitates a seamless development experience but requires careful handling to prevent misuse.

The vulnerability identified in the Vite Dev Server allows unauthorized attackers to read arbitrary files from the server's filesystem. The issue stems from improper restrictions in the fetchModule method within the WebSocket endpoint, which, when exploited, can bypass typical file system access controls. This flaw poses a significant risk, especially when the dev server is exposed to untrusted networks. The attacker does not need authentication, making it highly exploitable in open network environments. The severity of this vulnerability is largely due to the potential exposure of sensitive files and data. Proper patching and network hygiene are crucial to mitigate this risk.

Technically, the vulnerability manifests when an unauthenticated user connects to the Vite dev server's WebSocket endpoint and sends a crafted event to the fetchModule method. By crafting this event to include a file:// URL, attackers can retrieve contents of sensitive files, like /etc/passwd. The endpoint in question is vulnerable because it fails to enforce FS module access restrictions present elsewhere in the server. This flawed logic opens up the entire server's file system to unauthorized reads, disregarding the intended file access management strategies. Developers utilizing Vite must be vigilant and apply necessary patches to protect their environments.

If exploited, malicious actors can potentially read sensitive files, such as password files, SSH keys, and application configuration files, leading to significant data breaches. This could inadvertently expose personally identifiable information (PII), credentials, and other secrets, resulting in unauthorized access and subsequent exploitation. Furthermore, attackers could leverage this information to escalate privileges or conduct more sophisticated attacks. It's imperative to consider these repercussions when assessing the security posture of systems utilizing Vite Dev Server.

REFERENCES

Solution Advice
  • Upgrade Vite to the latest patched version: 8.0.5, 7.3.2, or 6.4.2 or later.
  • Prevent exposing the Vite dev server to untrusted networks.
  • Avoid using the --host 0.0.0.0 option on production or public interfaces.
  • Implement strict firewall rules to mitigate unauthorized access attempts.
  • Regularly audit server configurations to ensure non-exposure of sensitive endpoints.

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