The SVG Support plugin for WordPress is vulnerable to Stored Cross-Site Scripting via SVG File uploads in all versions up to, and including, 2.5.10 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses the SVG file. By default, this can only be exploited by administrators, but the ability to upload SVG files can be extended to authors.
The SVG Support WordPress plugin before 2.5 does not properly handle SVG added via an URL, which could allow users with a role as low as author to perform Cross-Site Scripting attacks
The SVG Support WordPress plugin before 2.3.20 does not escape the "CSS Class to target" setting before outputting it in an attribute, which could allow high privilege users to perform Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed.