What is CVE-2026-14631?

CVE-2026-14631 is a medium-severity vulnerability in Webpack-Dev-Server, classified under Improper Input Validation. CVSS score: 5.3/10. Published 2026-07-03.

How severe is CVE-2026-14631?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Improper input validation in Webpack-Dev-Server

CVE-2026-14631

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.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

EPSS: 0.004 (33.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Affected products

Webpack-dev-server — versions 0, 5.2.6
Webpack.js Webpack-dev-server

Weakness classification (CWE)

References

ce714d77-add3-4f53-aff5-83d477b104bb (Patch, Mitigation, Vendor Advisory)
ce714d77-add3-4f53-aff5-83d477b104bb (Third Party Advisory)

Frequently asked questions

What is CVE-2026-14631?: CVE-2026-14631 is a medium-severity vulnerability in Webpack-Dev-Server, classified under Improper Input Validation. CVSS score: 5.3/10. Published 2026-07-03.
How severe is CVE-2026-14631?: Medium severity. CVSS v3 base score is 5.3 out of 10.