webpack-dev-server vulnerable to cross-origin source code exposure on non-HTTPS origins (webpack-dev-server webpack-dev-server)

CVE-2026-6402
MEDIUM 5.3

At a glance

Source
NVD
EPSS
EPSS 0.29 % · percentile 22 ()
State
PUBLISHED
Published
Updated
Assigner
openjs
NVD status
Analyzed

Description

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.

Weaknesses (CWE)

  • CWE-749 — Exposed Dangerous Method or Function

References

Scores

VersionScoreVectorScored by
CVSS 3.1MEDIUM 5.3CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:Nopenjs
CVSS 3.1MEDIUM 5.3CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:NNVD · ce714d77-add3-4f53-aff5-83d477b104bb (Secondary)
CVSS 3.1MEDIUM 6.5CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:NNVD · nvd@nist.gov (Primary)

Advisories

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
webpack-dev-server · webpack-dev-serveraffected 0 < 5.2.4 ; unaffected 5.2.4

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD