---
id: CVE-2026-114348
title: >-
  webpack-dev-server: webpack-dev-server: Information disclosure via malformed
  Host header (CVE-2026-114348)
summary: >-
  A flaw was found in webpack-dev-server. An unauthenticated remote attacker can
  exploit improper Host header validation in the open-editor endpoint to obtain
  sensitive technical information. By sending a request with a specially crafted
  Hos…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'
cvssSource: vendor
cwe:
  - CWE-209
  - CWE-1289
vendor: Red Hat
product: webpack-dev-server
affected:
  - webpack-dev-server >= 5.1.0 < 5.2.7
  - webpack-dev-server >= 6.0.0 < 6.1.0
published: '2026-10-22'
updated: '2026-10-23'
sourceUpdated: '2026-10-23T00:16:04+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-114348.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-114348.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-114348'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2558806'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-114348'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-114348'
  - url: 'https://cna.openjsf.org/security-advisories.html'
  - url: >-
      https://github.com/webpack/webpack-dev-server/security/advisories/GHSA-wqhc-fvfg-56q6
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00343
epssPercentile: 0.26563
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-22T12:54:40.727618Z'
ingestedAt: '2026-10-22T10:35:54.919Z'
---

## Overview

A flaw was found in webpack-dev-server. An unauthenticated remote attacker can exploit improper Host header validation in the open-editor endpoint to obtain sensitive technical information. By sending a request with a specially crafted Host header, the attacker triggers an internal server error that returns a full error stack trace. This exposes environment details, including local file system paths, module locations, and internal source code references.

## Vendor advisories

- **Red Hat VEX** · Moderate · updated 2026-10-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-114348.json)

**webpack-dev-server: webpack-dev-server: Information disclosure via malformed Host header** — rated Moderate by Red Hat. Released 2026-10-22, updated 2026-10-23.

Not affected:

- Red Hat Hardened Images

## Remediation

Refer to the advisory for fix availability.