# CVE-2018-14732: Missing Origin Validation in webpack-dev-server

> Attackers can steal developer code by connecting to the WebSocket server from any origin due to missing origin checks in webpack-dev-server.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 21 Sep 2018
- **Updated:** 5 Aug 2024
- **Also known as:** CLSA-2026-1784683093, GHSA-cf66-xwfp-gvc4

## What is CVE-2018-14732?

CVE-2018-14732 is a high-severity missing authorization vulnerability in n/a, published on 21 Sep 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2018-14732?

2 open source packages ship an affected version, including webpack-dev-server. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `webpack-dev-server` | npm | All versions | 3.1.11 |
| `webpack-dev-server` | npm | All versions | 3.1.11 |

Products: Webpack.js Webpack-Dev-Server.

## How do I fix CVE-2018-14732?

Upgrade webpack-dev-server to 3.1.11 or later.

## Is CVE-2018-14732 being exploited?

There is no known exploitation of CVE-2018-14732 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2026-112085](https://insights.sbomify.com/CVE-2026-112085/): webpack-dev-server vulnerable to cross-origin WebSocket access via proxied upgrades (high 8.2)
- [CVE-2025-30360](https://insights.sbomify.com/CVE-2025-30360/): webpack-dev-server users' source code may be stolen when they access a malicious web site with non-Chromium based browser (medium 6.5)
- [CVE-2026-114348](https://insights.sbomify.com/CVE-2026-114348/): webpack-dev-server vulnerable to information disclosure via Host validation bypass in the open-editor endpoint (medium 5.3)
- [CVE-2026-14631](https://insights.sbomify.com/CVE-2026-14631/): webpack-dev-server vulnerable to denial of service via a malformed Host or Origin header (medium 5.3)
- [CVE-2026-9595](https://insights.sbomify.com/CVE-2026-9595/): webpack-dev-server vulnerable to HMR WebSocket interception via permissive user proxies (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-14732 and fix it if it is affected.

What it is: CVE-2018-14732 is a high-severity missing authorization vulnerability in n/a, published on 21 Sep 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2018-14732 in the wild and no public exploit code.

Affected packages and fixed versions:
- webpack-dev-server (npm): affected all versions; fixed in 3.1.11
- webpack-dev-server (npm): affected all versions; fixed in 3.1.11

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2018-14732/ (Markdown: https://insights.sbomify.com/CVE-2018-14732/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-14732
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-14732
- OSV: https://osv.dev/vulnerability/CVE-2018-14732

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-14732/
Summaries are generated and may contain mistakes; the official description above is the record.