CVE-2026-14631

webpack-dev-server vulnerable to denial of service via a malformed Host or Origin header

Published Jul 3, 2026 CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
webpack-dev-server versions 5.2.5 and earlier terminate the whole Node.js process when an unauthenticated peer sends either a normal HTTP request with a malformed Host header or a WebSocket upgrade to the default /ws endpoint with a malformed Origin header. The malformed value causes an uncaught exception in the host-validation path and crashes the dev server. Impact is limited to availability of the development server, no data disclosure, no code execution. Patches: upgrade to webpack-dev-server 5.2.6. Workarounds: keep the dev server bound to localhost (the default) and do not expose it to untrusted networks.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-m28w-2pqf-7qgj webpack-dev-server vulnerable to denial of service via a malformed Host or Origin header
History
Type Values Removed Values Added
First Time appeared Webpack.js
Webpack.js webpack-dev-server
Vendors & Products Webpack.js
Webpack.js webpack-dev-server
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description webpack-dev-server versions 5.2.5 and earlier terminate the whole Node.js process when an unauthenticated peer sends either a normal HTTP request with a malformed Host header or a WebSocket upgrade to the default /ws endpoint with a malformed Origin header. The malformed value causes an uncaught exception in the host-validation path and crashes the dev server. Impact is limited to availability of the development server, no data disclosure, no code execution. Patches: upgrade to webpack-dev-server 5.2.6. Workarounds: keep the dev server bound to localhost (the default) and do not expose it to untrusted networks.
Title webpack-dev-server vulnerable to denial of service via a malformed Host or Origin header
Weaknesses CWE-20
CWE-248
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
openjs
Published
Updated
Jul 6, 2026, 3:54 PM
Reserved
Jul 3, 2026, 5:15 PM
Status
Analyzed
Published
Jul 3, 2026, 6:16 PM
Modified
Jul 7, 2026, 3:08 PM
Severity
Moderate
Public date
Jul 3, 2026, 5:23 PM