CVE-2026-14631
webpack-dev-server vulnerable to denial of service via a malformed Host or Origin header
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.
INFO
Published Date :
July 3, 2026, 6:16 p.m.
Last Modified :
July 7, 2026, 3:08 p.m.
Remotely Exploit :
No
Source :
ce714d77-add3-4f53-aff5-83d477b104bb
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | ce714d77-add3-4f53-aff5-83d477b104bb | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE |
Solution
- Upgrade webpack-dev-server to version 5.2.6 or later.
- Restrict dev server access to localhost.
- Avoid exposing the dev server to untrusted networks.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-14631.
| URL | 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 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-14631 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-14631
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-14631 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-14631 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jul. 07, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:webpack.js:webpack-dev-server:*:*:*:*:*:*:*:* versions up to (excluding) 5.2.6 Added Reference Type openjs: https://cna.openjsf.org/security-advisories.html Types: Third Party Advisory Added Reference Type openjs: https://github.com/webpack/webpack-dev-server/security/advisories/GHSA-m28w-2pqf-7qgj Types: Mitigation, Patch, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 06, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-14631', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-06T15:54:04.567228Z'} -
New CVE Received by ce714d77-add3-4f53-aff5-83d477b104bb
Jul. 03, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'webpack-dev-server', 'product': 'webpack-dev-server', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '5.2.6', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.2.6', 'versionType': 'semver'}], 'packageURL': 'pkg:npm/webpack-dev-server', 'defaultStatus': 'unaffected'}] 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Added CWE CWE-20 Added CWE CWE-248 Added Reference https://cna.openjsf.org/security-advisories.html Added Reference https://github.com/webpack/webpack-dev-server/security/advisories/GHSA-m28w-2pqf-7qgj