CVE-2025-30360: Webpack.js Webpack-Dev-Server

Medium severity, CVSS 6.5. EPSS: 0.3% chance of exploitation in the next 30 days.

webpack-dev-server allows users to use webpack with a development server that provides live reloading. Prior to version 5.2.1, webpack-dev-server users' source code may be stolen when you access a malicious web site with non-Chromium based browser. The `Origin` header is checked to prevent Cross-site WebSocket hijacking from happening, which was reported by CVE-2018-14732. But webpack-dev-server always allows IP address `Origin` headers. This allows websites that are served on IP addresses to connect WebSocket. An attacker can obtain source code via a method similar to that used to exploit CVE-2018-14732. Version 5.2.1 contains a patch for the issue.

Affected products

• Webpack.js Webpack-Dev-Server: before 5.2.1 (fixed in 5.2.1)

Published 2025-06-03. Last modified 2026-06-17.