webpack/webpack-dev-server · Security
webpack-dev-server vulnerable to denial of service via a malformed Host or Origin header
- GHSA ID
- GHSA-m28w-2pqf-7qgj
- CVE ID
- CVE-2026-14631
- Severity
- medium
- Published
- Updated
- CVSS
- 5.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- CVSS v3
- 5.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Description
Impact
An unauthenticated peer that can reach the webpack-dev-server process can terminate it by sending 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 header triggers an uncaught exception in the host-validation path and crashes the dev server process.
Patches
Fixed in webpack-dev-server 5.2.6 by treating malformed Host and Origin header values as invalid rather than throwing (see PR #5699).
Workarounds
Keep the dev server bound to localhost (the default) and do not expose it to untrusted networks.
CWEs
- CWE-20 · Improper Input Validation
- CWE-248 · Uncaught Exception
References
- https://github.com/webpack/webpack-dev-server/security/advisories/GHSA-m28w-2pqf-7qgj ↗
- https://nvd.nist.gov/vuln/detail/CVE-2026-14631 ↗
- https://github.com/webpack/webpack-dev-server/pull/5699 ↗
- https://github.com/webpack/webpack-dev-server/commit/f21ed0f44aceb6132abb591ee8b60d770b6e489f ↗
- https://cna.openjsf.org/security-advisories.html ↗
- https://github.com/advisories/GHSA-m28w-2pqf-7qgj ↗