What’s Vulnerable › Vulnerabilities

CVE-2026-6378: Maxi Blocks <= 2.1.9 - Authenticated (Author+) Stored Cross-Site Scripting via Style Card REST API

• Severity: medium (CVSS 6.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-02 · updated 2026-06-17
• Weakness: CWE-79

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.

Affected products

• ckp267 MaxiBlocks Builder | 17,000+ Design Assets, Patterns, Icons & Starter Sites: through 2.1.9

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
• https://plugins.trac.wordpress.org/browser/maxi-blocks/tags/2.1.10/core/class-maxi-api.php#L987
• https://plugins.trac.wordpress.org/browser/maxi-blocks/tags/2.1.9/core/class-maxi-api.php#L221
• https://plugins.trac.wordpress.org/browser/maxi-blocks/tags/2.1.9/core/class-maxi-api.php#L979
• https://plugins.trac.wordpress.org/browser/maxi-blocks/tags/2.1.9/core/class-maxi-style-cards.php#L197
• https://www.wordfence.com/threat-intel/vulnerabilities/id/22f05048-df38-4f26-82a3-53caac995283?source=cve

Get alerted when CVE-2026-6378 or the next vulnerability affects your stack