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 plugin for WordPress defaults to insecure settings in version 2.5 and 2.5.1. SVG files containing malicious javascript are not sanitized. While version 2.5 adds the ability to sanitize image as they are uploaded, the plugin defaults to disable sanitization and does not restrict SVG upload to only administrators. This allows authenticated attackers, with author-level privileges and higher, to upload malicious SVG files that can be embedded in posts and pages by higher privileged users. Additionally, the embedded JavaScript is also triggered on visiting the image URL, which allows an attacker to execute malicious code in browsers visiting that URL.

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.