Robin Image Optimizer 2.0.0 - 2.0.7 - Unauthenticated Stored XSS via WebP URL Delivery HTML Parser

The Robin Image Optimizer WordPress plugin before 2.0.8 does not escape values that its bundled HTML parser re-emits into element attributes when a non-default image delivery mode is enabled, allowing unauthenticated users to submit content that is stored and later executed as Cross-Site Scripting in the browser of any user viewing an affected page, including administrators.