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 they access a malicious web site. Because the request for classic script by a script tag is not subject to same origin policy, an attacker can inject a malicious script in their site and run the script. Note that the attacker has to know the port and the output entrypoint script path. Combined with prototype pollution, the attacker can get a reference to the webpack runtime variables. By using `Function::toString` against the values in `__webpack_modules__`, the attacker can get the source code. Version 5.2.1 contains a patch for the issue.
Advisories
Source ID Title
EUVD EUVD EUVD-2025-16767 webpack-dev-server users' source code may be stolen when they access a malicious web site
Github GHSA Github GHSA GHSA-4v9v-hfq4-rm2v webpack-dev-server users' source code may be stolen when they access a malicious web site
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 03 Oct 2025 10:15:00 +0900

Type Values Removed Values Added
First Time appeared Webpack.js
Webpack.js webpack-dev-server
CPEs cpe:2.3:a:webpack.js:webpack-dev-server:*:*:*:*:*:*:*:*
Vendors & Products Webpack.js
Webpack.js webpack-dev-server

Sat, 07 Jun 2025 04:00:00 +0900

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Moderate


Wed, 04 Jun 2025 03:15:00 +0900

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 04 Jun 2025 02:45:00 +0900

Type Values Removed Values Added
Description 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 they access a malicious web site. Because the request for classic script by a script tag is not subject to same origin policy, an attacker can inject a malicious script in their site and run the script. Note that the attacker has to know the port and the output entrypoint script path. Combined with prototype pollution, the attacker can get a reference to the webpack runtime variables. By using `Function::toString` against the values in `__webpack_modules__`, the attacker can get the source code. Version 5.2.1 contains a patch for the issue.
Title webpack-dev-server users' source code may be stolen when they access a malicious web site
Weaknesses CWE-749
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2025-06-03T17:50:03.130Z

Reserved: 2025-03-21T14:12:06.271Z

Link: CVE-2025-30359

cve-icon Vulnrichment

Updated: 2025-06-03T17:49:52.996Z

cve-icon NVD

Status : Analyzed

Published: 2025-06-03T18:15:25.243

Modified: 2025-10-03T01:12:23.030

Link: CVE-2025-30359

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-06-03T17:39:16Z

Links: CVE-2025-30359 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses