CVE-2025-30359

webpack-dev-server users' source code may be stolen when they access a malicious web site

Published Jun 3, 2025 CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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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
History
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
Type Values Removed Values Added
Metrics ssvc

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

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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jun 3, 2025, 5:50 PM
Reserved
Mar 21, 2025, 2:12 PM
Status
Analyzed
Published
Jun 3, 2025, 6:15 PM
Modified
Jun 17, 2026, 9:08 AM
Severity
Moderate
Public date
Jun 3, 2025, 5:39 PM