webpack-dev-server vulnerable to denial of service via a malformed Host or Origin header

中 5.3CVE-2026-14631 · GHSA-m28w-2pqf-7qgj · 03/07/2026 公開 · 07/07/2026 更新

要点

CVE-2026-14631 は webpack-dev-server (webpack.js), webpack-dev-server に影響する深刻度「中」 (CVSS 5.3) の脆弱性です。
今後30日間に悪用される確率（EPSS）：0.52%（全脆弱性の 44.0% より高い）。
対処：5.2.6 以降に更新してください。

パッケージ	影響を受けるバージョン	修正済みバージョン
webpack-dev-server webpack.js	`< 5.2.6`	`5.2.6`
webpack-dev-server npm	`< 5.2.6`	`5.2.6`

概要

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.

NVD の説明

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.