# CVE-2026-112085: webpack-dev-server vulnerable to cross-origin WebSocket access via proxied upgrades


- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 22 Oct 2026
- **Updated:** 22 Oct 2026
- **Also known as:** AZL-111065, GHSA-cfqc-fj3v-j925, UBUNTU-CVE-2026-112085

## What is CVE-2026-112085?

CVE-2026-112085 is a high-severity vulnerability in webpack-dev-server, published on 22 Oct 2026. 

### Official description

webpack-dev-server is a development server that provides live reloading for webpack projects. In versions before 5.2.7 and in version 6.0.0, when a proxy entry is configured to forward WebSockets, the server forwards non-HMR WebSocket upgrade requests to the proxy target without validating the Host or Origin headers, so the allowedHosts protection does not apply to those proxied upgrades. A malicious web page visited by a developer can open a cross-origin WebSocket through the dev server and read from and write to the proxied backend, even when the server is bound to loopback. The issue is fixed in webpack-dev-server 5.2.7 and 6.1.0, where proxied WebSocket upgrades pass the same Host and Origin validation as the HMR WebSocket, and users should upgrade to one of those versions or later. As a workaround, omit WebSocket forwarding from proxy entries that do not need it and scope the proxy to specific paths.

Weakness: CWE-346 (Origin Validation Error), CWE-1385 (Missing Origin Validation in WebSockets)

## Which versions are affected by CVE-2026-112085?

It affects 1 product.


Products: Webpack.js Webpack-Dev-Server.

## How do I fix CVE-2026-112085?

Upgrade to a fixed version.

## Is CVE-2026-112085 being exploited?

There is no known exploitation of CVE-2026-112085 in the wild and no public exploit code.

## Other vulnerabilities in webpack-dev-server

- [CVE-2018-14732](https://insights.sbomify.com/CVE-2018-14732/): Missing Origin Validation in webpack-dev-server (high 7.5)
- [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-2026-112085 and fix it if it is affected.

What it is: CVE-2026-112085 is a high-severity vulnerability in webpack-dev-server, published on 22 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-112085 in the wild and no public exploit code.

Affected product: webpack-dev-server. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-112085/ (Markdown: https://insights.sbomify.com/CVE-2026-112085/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-112085
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-112085
- OSV: https://osv.dev/vulnerability/CVE-2026-112085

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-112085/
Summaries are generated and may contain mistakes; the official description above is the record.