The Robin Image Optimizer – Unlimited Image Optimization & WebP Converter plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'Alternative Text' field of a Media Library image in all versions up to, and including, 2.0.2 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 an injected page.