CVE-2018-14732 is a high-severity (CVSS 7.5) Improper Input Validation vulnerability in webpack-dev-server. 2 public exploit references exist, so weaponization risk is real. A fix is available for webpack-dev-server — see the affected versions and patch details below.
Missing Origin Validation in webpack-dev-server
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2018-14732 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 394,803 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
webpack-dev-servernpmDescription
An issue was discovered in lib/Server.js in webpack-dev-server before 3.1.6. Attackers are able to steal developer's code because the origin of requests is not checked by the WebSocket server, which is used for HMR (Hot Module Replacement). Anyone can receive the HMR message sent by the WebSocket server via a ws://127.0.0.1:8080/ connection from any origin.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | webpack-dev-server | all versions | 3.1.11npm install webpack-dev-server@3.1.11 |
Affected Products
webpack-dev-serverwebpack.jsResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for webpack-dev-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update webpack-dev-server to 3.1.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-14732 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2018-14732 in your dependencies?
Find it across npm, including transitive dependencies.