webpack-dev-server vulnerable to information disclosure via Host validation bypass in the open-editor endpoint
webpack-dev-server is a development server that provides live reloading for webpack projects. In versions from 5.1.0 before 5.2.7 and in version 6.0.0, the unauthenticated open-editor endpoint validates the Host header with a regular expression meant for browser Origin schemes, so a Host value beginning with file: or with an extension scheme short-circuits the hostname and allowedHosts checks. A network peer that can reach the dev server can send a request with a malformed Host that passes validation and then causes the endpoint's URL construction to throw, and in the default non-production mode the server returns an HTTP 500 body containing the full exception stack trace, which discloses absolute filesystem paths, installed module locations, and internal source line numbers. The server keeps running, so there is no denial of service. The issue is fixed in webpack-dev-server 5.2.7 and 6.1.0, and users should upgrade to one of those versions or later.
CVE-2026-114348
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-114348
webpack-dev-server
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "webpack-dev-server",
"product": "webpack-dev-server",
"versions": [
{
"status": "affected",
"version": "5.1.0",
"lessThan": "5.2.7",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.2.7",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.0.0",
"lessThan": "6.1.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.0",
"versionType": "semver"
}
],
"packageURL": "pkg:npm/webpack-dev-server",
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-114348
Source reference:
/cveMetadata/cveId
Publisher severity
medium
Source reference: /containers/cna/metrics
- Event
- #50244 · Revision 1
- Added to Heist Feed
- Publisher date