Source disclosure via unrestricted cross-origin script loading
Published Jun 3, 2025 · Updated Jun 3, 2025
Information disclosure in webpack webpack-dev-server before 5.2.1 allows remote attackers to read bundled source via cross-origin script loading. The development server accepts cross-site classic-script requests, letting prototype pollution of Array.prototype.forEach capture webpack_require and stringify webpack_modules. A user must visit a malicious site while the server is reachable, and the attacker must know its port and entrypoint path; the reported consequence is source-code disclosure only.
Summary
What happened
Information disclosure in webpack webpack-dev-server before 5.2.1 allows remote attackers to read bundled source via cross-origin script loading. The development server accepts cross-site classic-script requests, letting prototype pollution of Array.prototype.forEach capture webpack_require and stringify webpack_modules. A user must visit a malicious site while the server is reachable, and the attacker must know its port and entrypoint path; the reported consequence is source-code disclosure only.
The record
- CVE
- CVE-2025-30359
- Published
- Jun 3, 2025
- Updated
- Jun 3, 2025
- Vendor
- webpack
- Product
- webpack-dev-server
- Classifications
- CWE-749, T1189
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 3, 2025CVE publishedPublication date reported by the CVE source.
- Jun 3, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 5.2.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- GHSA-4v9v-hfq4-rm2v proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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