The HT Mega – Absolute Addons For Elementor plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's Gutenberg blocks in all versions up to, and including, 3.0.0 due to insufficient input validation on user-supplied HTML tag names. This is due to the lack of a tag name whitelist allowing dangerous tags like 'script', 'iframe', and 'object' to be injected even though tag_escape() is used for sanitization. While some blocks use esc_html() for content, this can be bypassed using JavaScript encoding techniques (unquoted strings, backticks, String.fromCharCode()). 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.