The Easy Appointments WordPress plugin through 3.12.26 does not correctly validate shortcode input in one of its block-rendering actions, checking only the first tag of the supplied string against an…

Summary

The Easy Appointments WordPress plugin through 3.12.26 does not correctly validate shortcode input in one of its block-rendering actions, checking only the first tag of the supplied string against an allowlist while rendering the entire string, allowing users with contributor-level access to execute arbitrary registered shortcodes.