CVE-2026-14631

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.

CVSS v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://cna.openjsf.org/security-advisories.html	Third Party Advisory
https://github.com/webpack/webpack-dev-server/security/advisories/GHSA-m28w-2pqf-7qgj	Mitigation Vendor Advisory Patch

Configurations

Configuration 1 (hide)

cpe:2.3:a:webpack.js:webpack-dev-server:*:*:*:*:*:*:*:*

History

07 Jul 2026, 15:08

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 -~~	() https://cna.openjsf.org/security-advisories.html - Third Party Advisory
References	~~() https://github.com/webpack/webpack-dev-server/security/advisories/GHSA-m28w-2pqf-7qgj -~~	() https://github.com/webpack/webpack-dev-server/security/advisories/GHSA-m28w-2pqf-7qgj - Mitigation, Vendor Advisory, Patch

03 Jul 2026, 18:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-03 18:16

Updated : 2026-07-07 15:08

NVD link : CVE-2026-14631

Mitre link : CVE-2026-14631

CVE.ORG link : CVE-2026-14631

JSON object : View

Products Affected

webpack.js

webpack-dev-server

CWE

CWE-20

Improper Input Validation

CWE-248

Uncaught Exception

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