Intel

AIKIDO-2025-10940

inferno-server is vulnerable to CSS Injection

CSS Injection Pre-CVE
Found by Aikido Intel before public disclosure or CVE publication.
Published Dec 15, 2025

55

Medium Risk

This Affects:

JSinferno-server
3.6.0 - 9.0.6
Fixed in 9.0.7
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TL;DR

Affected versions of this package are vulnerable due to a flaw in inferno-server's server-side rendering pipeline where the style prop bypasses HTML entity escaping during renderToString() or renderToStringStream(), allowing an attacker who controls an untrusted style value (e.g., from a CMS, theme, or user API) to inject raw attributes like onmouseover by breaking out of the style context, leading to Cross-Site Scripting (XSS).

Who does this affect?

You are affected if you are using a version that falls within the vulnerable range.

Background info

inferno-server is vulnerable to CSS Injection in versions 3.6.0 - 9.0.6.

How to fix this

Upgrade the inferno-server library to the patch version.