Vulnerability in Webpack Webpack-Dev-Server

CVE-2025-30360

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.

EPSS: 0.003 (21.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-30360?
CVE-2025-30360 is a medium-severity vulnerability in Webpack Webpack-Dev-Server, classified under Origin Validation Error. CVSS score: 6.5/10. Published 2025-06-03.
How severe is CVE-2025-30360?
Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2025-30360 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.