Dashboard / CVE-2026-112085

CVE-2026-112085

HIGH
MEDIUM Priority: 0.01 BB Relevance: 66/100
Published: 2026-10-22 Modified: 2026-10-29 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth Conf. Impact Scope Change

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: Required
S: Changed
C: High
I: Low
A: None

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 Classification (2)

Affected Software (1)

VendorProductVersion
webpack.js webpack-dev-server < 5.2.7

References & Advisories (2)

Bug Bounty Relevance

66 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity

CVSS Score

8.2 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N

EPSS — Exploitation Probability

0.15%
Raw Score 0.001470
Percentile 3.9%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00147
2026-10-28
0.00147

Intelligence Sources

nvd ref →

External Links