The Smash Balloon Social Photo Feed – Easy Social Feeds Plugin plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the `data-plugin` attribute in all versions up to, and including, 6.9.0 (Free) and 6.8.0 (Pro) 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.