fkie_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.

GHSA-w27v-7q3p-w38r — SVGO: removeScripts allows executable links through namespace and control-character bypasses

Affected: npm: svgo

## Summary

SVGO's opt-in `removeScripts` plugin failed to remove some executable links. Namespace-prefixed SVG anchors and URL schemes containing ASCII tabs or newlines could bypass its checks. Applications that used this plugin as their only protection for untrusted SVG input could expose users to cross-site scripting (XSS).

SVGO is an optimizer rather than a comprehensive sanitization library, but `removeScripts` is maintained for consumers that already rely on it to remove common script execution paths.

## Details

Two related bypasses were present:

1. The plugin inspected unprefixed SVG `<a>` elements but did not recognize namespace-prefixed SVG anchors such as `<svg:a>` when the prefix was bound to the SVG namespace. Their executable `href` or namespaced `*:href` values remained intact. 2. The URL check did not account for ASCII tab, line-feed, or carriage-return characters embedded in a scheme. Browsers remove these characters before parsing the scheme, so values such as `java	script:` could remain executable after bypassing the plugin's `javascript:` check.

Anchors in unrelated custom namespaces are not executable SVG anchors and remain untouched.

## Impact

If an application optimized attacker-controlled SVGs with `removeScripts` and then served the result in an active browser context, a victim could follow a link that executes script in the SVG's origin. Depending on the embedding and origin configuration, this could expose cookies or local storage, modify…

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fkie_cve-2026-84370

GHSA-w27v-7q3p-w38r — SVGO: removeScripts allows executable links through namespace and control-character bypasses