The Niche Hero | Beautifully-designed blocks in seconds plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'spacing' parameter of the nh_row shortcode in all versions up to, and including, 1.0.5 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
https://plugins.trac.wordpress.org/browser/niche-hero/trunk/niche-hero.php#L302
https://plugins.trac.wordpress.org/browser/niche-hero/tags/1.0.5/niche-hero.php#L302