CVE-2026-6378

Description

The Maxi Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the `/wp-json/maxi-blocks/v1.0/style-card` REST API endpoint in all versions up to, and including, 2.1.9 due to insufficient input sanitization and output escaping of the `sc_styles` parameter. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts that execute on every page where the plugin's style card styles are loaded, including across the entire WordPress admin panel.

References

• https://github.com/maxi-blocks/maxi-blocks/pull/6250/changes/8db3267df9858f684e420566227ed2ea7954d9a9
• https://plugins.trac.wordpress.org/browser/maxi-blocks/tags/2.1.10/core/class-maxi-api.php#L1010
• https://plugins.trac.wordpress.org/browser/maxi-blocks/tags/2.1.10/core/class-maxi-api.php#L1021
• https://plugins.trac.wordpress.org/browser/maxi-blocks/tags/2.1.10/core/class-maxi-api.php#L979
• https://plugins.trac.wordpress.org/browser/maxi-blocks/tags/2.1.10/core/class-maxi-api.php#L981