webpack-dev-server versions up to and including 5.2.3 are vulnerable to cross-origin source code exposure when serving over a non-potentially trustworthy origin such as plain HTTP. The previous fix relied on the Sec-Fetch-Mode and Sec-Fetch-Site request headers, which browsers omit for non-trustworthy origins, allowing a malicious site to load the bundled source as a script and read it across origins. Impact: an attacker controlling a website visited by a developer running webpack-dev-server can recover the application source code when the dev server runs over HTTP at a guessable host and port. Chromium based browsers from Chrome 142 onward are not affected due to local network access restrictions. Upgrade to webpack-dev-server 5.2.4 or later, which sets Cross-Origin-Resource-Policy: same-origin on responses.
References
| Link | Resource |
|---|---|
| https://cna.openjsf.org/security-advisories.html | Vendor Advisory |
| https://github.com/webpack/webpack-dev-server/security/advisories/GHSA-79cf-xcqc-c78w | Mitigation Vendor Advisory |
Configurations
History
18 May 2026, 15:23
| Type | Values Removed | Values Added |
|---|---|---|
| CPE | cpe:2.3:a:webpack.js:webpack-dev-server:*:*:*:*:*:*:*:* | |
| First Time |
Webpack.js webpack-dev-server
Webpack.js |
|
| References | () https://cna.openjsf.org/security-advisories.html - Vendor Advisory | |
| References | () https://github.com/webpack/webpack-dev-server/security/advisories/GHSA-79cf-xcqc-c78w - Mitigation, Vendor Advisory |
12 May 2026, 09:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-05-12 09:16
Updated : 2026-05-18 15:23
NVD link : CVE-2026-6402
Mitre link : CVE-2026-6402
CVE.ORG link : CVE-2026-6402
JSON object : View
Products Affected
webpack.js
- webpack-dev-server
CWE
CWE-749
Exposed Dangerous Method or Function