XSS in Svg Svgo

CVE-2026-84370

SVGO, short for SVG Optimizer, is a Node.js library and command-line application for optimizing SVG files. From version 1.0.0 until versions 2.8.4, 3.3.5, and 4.1.0, the opt-in removeScripts plugin, named removeScriptElement in versions 2 and 3, incompletely filters executable links in plugins/removeScripts.js and lib/svgo/tools.js. The plugin does not recognize namespace-prefixed SVG anchor elements such as svg:a with href or namespaced *:href values, and it does not remove ASCII tab, line-feed, or carriage-return characters before checking URL schemes. Browsers remove those characters before parsing a scheme, allowing an executable link to pass the plugin's check. When an application processes attacker-controlled SVG input and serves the result in an active browser context, a victim who activates the surviving link can execute script in the SVG's origin, expose data, modify content, or perform actions as the victim. This issue is fixed in versions 2.8.4, 3.3.5, and 4.1.0.

Vulnerability class: XSS (Cross-Site Scripting)

CVSS v3 metric

CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N.

Affected products

  • Svg Svgo — versions >= 1.0.0, < 2.8.4, >= 3.0.0, < 3.3.5, >= 4.0.0, < 4.1.0

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-84370?
CVE-2026-84370 is a high-severity vulnerability in Svg Svgo, classified under Cross-site Scripting. CVSS score: 8.2/10. Published 2026-09-01.
How severe is CVE-2026-84370?
High severity. CVSS v3 base score is 8.2 out of 10.