CVE-2026-39363: Vite arbitrary file read via dev server WebSocket

CVE-2026-39363 · Severity: high · CVSS 7.5 · Published 2026-04-07

Vite is a popular development tool used by software engineers to build and test web applications. A security flaw in its development server allows unauthorized users to bypass security restrictions and read sensitive files from the developer's computer or build environment. This could lead to the exposure of source code, configuration files, or credentials if the development server is exposed to a network.

Technologies: Vite, Vite. Vendors: Vite.

Quick answers

Is CVE-2026-39363 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-39363 being exploited in the wild.
How severe is CVE-2026-39363?
High severity, with a CVSS score of 7.5, published 7 April 2026.
Which products and versions are affected?
Vite >=6.0.0, <6.4.2; >=7.0.0, <7.3.2; >=8.0.0, <8.0.5; Vite SEMVER:introduced=8.0.0,fixed=8.0.5.
Is there a fix for CVE-2026-39363?
Yes. Vite: upgrade to 8.0.5 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-39363 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-39363?
Check whether you run Vite or Vite at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • Vite: upgrade to 8.0.5 or later

Technical details

An information disclosure vulnerability exists in the Vite development server due to insufficient access control enforcement on the WebSocket execution path. While the HTTP request path correctly enforces 'server.fs.allow' restrictions, the 'fetchModule' method exposed via the 'vite:invoke' WebSocket event does not. An attacker can connect to the WebSocket without an Origin header and use 'file://' URIs combined with the '?raw' or '?inline' query parameters to retrieve arbitrary local files as JavaScript strings. This exploit requires the Vite dev server to be bound to a network-accessible interface (e.g., via --host) and for the WebSocket server to be enabled.

Affected products

  • Vite Vite >=6.0.0, <6.4.2; >=7.0.0, <7.3.2; >=8.0.0, <8.0.5
  • Vite vite-plus <=0.1.15
  • Red Hat Ansible Automation Platform 2.5, 2.6

Identifiers

  • CVE-2026-39363
  • GHSA-p9ff-h696-f583

Timeline

  • 2026-04-06: advisory: GitHub Security Advisory published by Vite maintainers
  • 2026-04-07: disclosed: NVD publication date
  • 2026-06-09: patched: Red Hat released security updates for Ansible Automation Platform

References

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