CVE-2026-6402
CVE-2026-6402 · webpack-dev-server vulnerable to cross-origin source code exposure on non-HTTPS origins
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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.
CVSS 5.3 · Medium · EPSS 0.3% · Fix available
- Published
- Updated
Stack: node
Affected products and versions
webpack-dev-server
- Versions
- ≥ 0, < 5.2.4: Affected (semver)
- 5.2.4: Not affected (semver)
Update to 5.2.4
webpack-dev-server npm
- Affected ranges
- SEMVER: < 5.2.4
Update to 5.2.4