Information Exposure Affecting webpack-dev-server package, versions >=5.1.0 <5.2.7>=6.0.0 <6.1.0
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published22 Oct 2026
- disclosed22 Oct 2026
- creditDaniel Coles, manus-use
Introduced: 22 Oct 2026
NewCVE-2026-114348 (opens in a new tab)How to fix?
Upgrade webpack-dev-server to version 5.2.7, 6.1.0 or higher.
Overview
webpack-dev-server is an Uses webpack with a development server that provides live reloading. It should be used for development only.
Affected versions of this package are vulnerable to Information Exposure via the isValidHost method in lib/Server.js, where Host and :authority headers are not properly validated against malformed or URL-encoded values. An attacker can send a request with a malformed Host header that bypasses the allowedHosts check, allowing unauthorized access to the webpack-dev-server. Additionally, the editor URL handler constructs a URL using the untrusted Host header as the base, which can be exploited to cause unexpected behavior through a malformed request.