CVE-2026-14631 webpack-dev-server vulnerable to denial of service via a malformed Host or Origin header

webpack-dev-server versions 5.2.5 and earlier terminate the whole Node.js process when an unauthenticated peer sends either a normal HTTP request with a malformed Host header or a WebSocket upgrade to the default /ws endpoint with a malformed Origin header. The malformed value causes an uncaught...

CVE-2026-14620

webpack-dev-server versions 5.2.5 and earlier expose two internal developer endpoints, /webpack-dev-server/open-editor and /webpack-dev-server/invalidate, that perform state-changing actions on any GET request without verifying that the request originated from the dev server's own page. Any websi...

CVE-2026-14620

webpack-dev-server versions 5.2.5 and earlier expose two internal developer endpoints, /webpack-dev-server/open-editor and /webpack-dev-server/invalidate, that perform state-changing actions on any GET request without verifying that the request originated from the dev server's own page. Any websi...

CVE-2026-14620 webpack-dev-server vulnerable to cross-site request forgery via internal developer endpoints

webpack-dev-server versions 5.2.5 and earlier expose two internal developer endpoints, /webpack-dev-server/open-editor and /webpack-dev-server/invalidate, that perform state-changing actions on any GET request without verifying that the request originated from the dev server's own page. Any websi...

CVE-2026-14620

webpack-dev-server prior to 5.2.6 exposes two internal endpoints (/webpack-dev-server/open-editor and /webpack-dev-server/invalidate) that perform state-changing actions on any GET request without origin verification. This enables cross-origin interactions when a user visits any website while the...

CVE-2026-14620 webpack-dev-server vulnerable to cross-site request forgery via internal developer endpoints

webpack-dev-server versions 5.2.5 and earlier expose two internal developer endpoints, /webpack-dev-server/open-editor and /webpack-dev-server/invalidate, that perform state-changing actions on any GET request without verifying that the request originated from the dev server's own page. Any websi...

PT-2026-55575

Name of the Vulnerable Software and Affected Versions webpack-dev-server versions prior to 5.2.6 Description Internal developer endpoints '/webpack-dev-server/open-editor' and '/webpack-dev-server/invalidate' perform state-changing actions on GET requests without verifying the request origin. Thi...

CVE-2026-9595

A flaw was found in webpack-dev-server. When a user configures a proxy with a broad context, such as '/', and enables WebSocket ws: true forwarding, the development server's own Hot Module Replacement HMR WebSocket can be intercepted. This interception leads to the leakage of the browser's cookie...

Linux Distros Unpatched Vulnerability : CVE-2026-9595

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - Impact: When a user-configured proxy on webpack-dev-server has a broad context e.g. / and ws: true, it also intercepts the dev server's own HMR WebSocket and...

GHSA-MX8G-39Q3-5C79 webpack-dev-server vulnerable to HMR WebSocket interception via permissive user proxies

Impact When a user-configured proxy on webpack-dev-server has a broad context e.g. / and ws: true, it also intercepts the dev server's own HMR WebSocket and forwards it to the proxy target. This leaks the browser's cookies and Origin header to the backend, bypasses the dev server's Host/Origin...

EUVD-2026-36729

webpack-dev-server vulnerable to HMR WebSocket interception via permissive user proxies...

Unintended Proxy or Intermediary ('Confused Deputy')

Overview webpack-dev-server is an Uses webpack with a development server that provides live reloading. It should be used for development only. Affected versions of this package are vulnerable to Unintended Proxy or Intermediary 'Confused Deputy' via permissive user proxy configurations that inclu...

Unintended Proxy or Intermediary ('Confused Deputy')

Overview org.webjars.npm:webpack-dev-server is an Uses webpack with a development server that provides live reloading. It should be used for development only. Affected versions of this package are vulnerable to Unintended Proxy or Intermediary 'Confused Deputy' via permissive user proxy...

CVE-2026-9595

Impact: When a user-configured proxy on webpack-dev-server has a broad context e.g. / and ws: true, it also intercepts the dev server's own HMR WebSocket and forwards it to the proxy target. This leaks the browser's cookies and Origin header to the backend, bypasses the dev server's Host/Origin...

UBUNTU-CVE-2026-9595

Impact: When a user-configured proxy on webpack-dev-server has a broad context e.g. / and ws: true, it also intercepts the dev server's own HMR WebSocket and forwards it to the proxy target. This leaks the browser's cookies and Origin header to the backend, bypasses the dev server's Host/Origin...

CVE-2026-9595 webpack-dev-server vulnerable to HMR WebSocket interception via permissive user proxies

Impact: When a user-configured proxy on webpack-dev-server has a broad context e.g. / and ws: true, it also intercepts the dev server's own HMR WebSocket and forwards it to the proxy target. This leaks the browser's cookies and Origin header to the backend, bypasses the dev server's Host/Origin...

CVE-2026-9595

The CVE affects webpack-dev-server where a user-configured proxy with a broad context (e.g., /) and ws: true intercepts the dev server’s HMR WebSocket, forwarding it to the proxy target. This can leak cookies and Origin headers to the backend, bypass Host/Origin validation, and corrupt the HMR so...

CVE-2026-9595 webpack-dev-server vulnerable to HMR WebSocket interception via permissive user proxies

Impact: When a user-configured proxy on webpack-dev-server has a broad context e.g. / and ws: true, it also intercepts the dev server's own HMR WebSocket and forwards it to the proxy target. This leaks the browser's cookies and Origin header to the backend, bypasses the dev server's Host/Origin...

PT-2026-49244

Name of the Vulnerable Software and Affected Versions webpack-dev-server versions prior to 5.2.5 Description A permissive user-configured proxy with a broad context e.g., '/' and ws: true intercepts the development server's own Hot Module Replacement HMR WebSocket and forwards it to the proxy...

GHSA-79CF-XCQC-C78W webpack-dev-server vulnerable to cross-origin source code exposure on non-HTTPS origins

Impact When webpack-dev-server is running on a non-HTTPS origin the default, cross-origin requests from malicious websites can load the dev server's JavaScript bundles via tags. The fix introduced in v5.2.1 CVE-2025-30359 relied on Sec-Fetch-Mode and Sec-Fetch-Site request headers to block these...