A vulnerability classified as problematic has been found in Flask-RESTX up to 0.5.0. Affected is the function
email_regex of the component Regular Expression Handler. Upgrading to version 0.5.1 eliminates this vulnerability. Applying the patch bab31e085f355dd73858fd3715f7ed71849656da is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.