GHSA-m28w-2pqf-7qgjMediumCVSS 5.3
webpack-dev-server vulnerable to denial of service via a malformed Host or Origin header
🔗 CVE IDs covered (1)
📋 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.
🎯 Affected products1
- npm/webpack-dev-server:<= 5.2.5
🔗 References (6)
- 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