Converter for Media <= 6.3.2 - Missing Authorization to Authenticated (Subscriber+) Optimized Image Deletion via regenerate-attachment REST Endpoint

The Converter for Media – Optimize images | Convert WebP & AVIF plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the `/webp-converter/v1/regenerate-attachment` REST endpoint in all versions up to, and including, 6.3.2. This makes it possible for authenticated attackers, with Subscriber-level access and above, to delete optimized WebP/AVIF variants for arbitrary attachments.