CVE-2026-112085

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure.

Exploit odds

0.1% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-10-18 15:33 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-10-22 10:17 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-10-29 13:50 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.1% in the next 30 days (EPSS).
• Severity: 8.2 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-10-22 10:17 UTC

Last modified

2026-10-29 13:50 UTC

Exploit probability

0.1% · EPSS, next 30 days

Weakness

CWE-346

Record status

Analyzed

Affected

• webpack.js webpack-dev-server < 5.2.7
• webpack.js webpack-dev-server < 6.1.0

Attack profile CVSS 3.1 · 8.2

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

Required

Scope

Changed

Confidentiality

High

Integrity

Low

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-112085.md and follow it. Check whether this project is affected by CVE-2026-112085. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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