Description
Fabric.js is a Javascript HTML5 canvas library. Prior to version 7.2.0, Fabric.js applies `escapeXml()` to text content during SVG export (`src/shapes/Text/TextSVGExportMixin.ts:186`) but fails to apply it to other user-controlled string values that are interpolated into SVG attribute markup. When attacker-controlled JSON is loaded via `loadFromJSON()` and later exported via `toSVG()`, the unescaped values break out of XML attributes and inject arbitrary SVG elements including event handlers. Any application that accepts user-supplied JSON (via `loadFromJSON()`, collaborative sharing, import features, CMS plugins) and renders the `toSVG()` output in a browser context (SVG preview, export download rendered in-page, email template, embed) is vulnerable to stored XSS. An attacker can execute arbitrary JavaScript in the victim's browser session. Version 7.2.0 contains a fix.
Problem types
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-116: Improper Encoding or Escaping of Output
Product status
References
github.com/...ric.js/security/advisories/GHSA-hfvx-25r5-qc3w
github.com/...ommit/7e1a122defd8feefe4eb7eaf0c180d7b0aeb6fee
github.com/fabricjs/fabric.js/releases/tag/v720