This module implements a field formatter for text fields that improves the Summary or Trimmed formatter built into Drupal core.
The module doesn't sufficiently escape unsafe HTML when passed through the module's Twig filter.
This vulnerability is mitigated by the fact that an attacker must have a role with the ability to post content that gets passed through a Twig template with one of the |smart_trim_* filters provided by this module.
If a site uses only use the field formatter without the Twig filter, it is not vulnerable.