CVE-2026-14631: medium-severity vulnerability in webpack-dev-server
webpack-dev-server vulnerable to denial of service via a malformed Host or Origin header
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.3epss 0.5%
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Affected products
webpack-dev-server · webpack-dev-serverRelated CVEs — webpack-dev-server
In the same product, most dangerous first.
CVE-2026-14620MEDIUMwebpack-dev-server vulnerable to cross-site request forgery via internal developer endpointsEPSS 0.5%CVE-2026-114348MEDIUMwebpack-dev-server vulnerable to information disclosure via Host validation bypass in the open-editor endpointEPSS 0.3%CVE-2026-6402MEDIUMwebpack-dev-server vulnerable to cross-origin source code exposure on non-HTTPS originsEPSS 0.3%CVE-2026-9595MEDIUMwebpack-dev-server vulnerable to HMR WebSocket interception via permissive user proxiesEPSS 0.2%CVE-2026-112085HIGHwebpack-dev-server vulnerable to cross-origin WebSocket access via proxied upgradesEPSS 0.1%