{"id":"CVE-2026-6402","summary":"webpack-dev-server vulnerable to cross-origin source code exposure on non-HTTPS origins","details":"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.","aliases":["GHSA-79cf-xcqc-c78w"],"modified":"2026-07-08T22:29:20.256305385Z","published":"2026-05-12T07:45:21.253Z","related":["CGA-6rjx-x46x-xxjg","openSUSE-SU-2026:10979-1"],"database_specific":{"cwe_ids":["CWE-749"],"cna_assigner":"openjs","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6402.json"},"references":[{"type":"ADVISORY","url":"https://cna.openjsf.org/security-advisories.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6402.json"},{"type":"ADVISORY","url":"https://github.com/webpack/webpack-dev-server/security/advisories/GHSA-79cf-xcqc-c78w"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-6402"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/webpack/webpack-dev-server","events":[{"introduced":"0"},{"fixed":"fd401308f1cc026262880e2dab810004d6444282"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"5.2.4"}],"source":["AFFECTED_FIELD","CPE_RANGE"],"cpe":"cpe:2.3:a:webpack.js:webpack-dev-server:*:*:*:*:*:*:*:*"}}],"versions":["v5.2.3","v5.2.2","v5.2.1","v5.2.0","v5.1.0","v5.0.4","v4.15.1","v5.0.3","v5.0.2","v5.0.1","v5.0.0","v4.15.0","v4.14.0","v4.13.3","v4.13.2","v4.13.1","v4.13.0","v4.12.0","v4.11.1","v4.11.0","v4.10.1","v4.10.0","v4.9.3","v4.9.2","v4.9.1","v4.9.0","v4.8.1","v4.8.0","v4.7.4","v4.7.3","v4.7.2","v4.7.1","v4.7.0","v4.6.0","v4.5.0","v4.4.0","v4.3.1","v4.3.0","v4.2.1","v4.2.0","v4.1.1","v4.1.0","v4.0.0","v4.0.0-rc.1","v4.0.0-rc.0","v4.0.0-beta.3","v4.0.0-beta.2","v4.0.0-beta.1","v3.11.0","v4.0.0-beta.0","v3.10.3","v3.10.2","v3.10.0","v3.9.0","v3.8.2","v3.8.1","v3.8.0","v3.7.2","v3.7.1","v3.7.0","v3.5.1","v3.5.0","v3.4.1","v3.4.0","v3.3.1","v3.3.0","v3.2.1","v3.2.0","v3.1.14","v3.1.13","v3.1.12","v3.1.11","v3.1.10","v3.1.9","v3.1.8","v3.1.7","v3.1.6","v3.1.5","v3.1.4","v3.1.3","v3.1.2","v3.1.1","v3.1.0","v3.0.1-beta.0","v3.0.0","v2.11.1","v2.11.0","v2.10.1","v2.10.0","v2.9.7","v2.9.6","v2.9.5","v2.9.3","v2.9.2","v2.9.1","v2.9.0","v2.8.2","v2.8.1","v2.8.0","v2.6.1","v2.6.0","v2.5.0","v2.4.5","v2.4.4","v2.4.3","v2.4.2","v2.4.1","v2.4.0","v2.3.0","v2.2.1","v2.2.0","v2.2.0-rc.0","v2.1.0-beta.12","v2.1.0-beta.11","v2.1.0-beta.10","v2.1.0-beta.9","v2.1.0-beta.8","v2.1.0-beta.7","v2.1.0-beta.6","v2.1.0-beta.5","v2.1.0-beta.4","v2.1.0-beta.3","v2.1.0-beta.2","v2.1.0-beta.1","v2.1.0-beta.0","v2.0.0-beta","v1.14.1","v1.14.0","v1.13.0","v1.12.1","v1.12.0","v1.11.0","v1.10.1","v1.10.0","v1.9.0","v1.8.2","v1.8.1","v1.8.0","v1.7.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-6402.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N"}]}