A cross-origin vulnerability has been discovered in the Auth0 auth0.js library affecting versions < 8.12. This vulnerability allows an attacker to acquire authenticated users' tokens and invoke services on a user's behalf if the target site or application uses a popup callback page with auth0.popup.callback().
https://github.com/advisories/GHSA-3rpr-mg43-xhq4
https://euvd.enisa.europa.eu/vulnerability/EUVD-2017-0359
https://auth0.com/docs/security/bulletins/cve-2017-17068
https://appcheck-ng.com/appcheck-discovers-vulnerability-auth0-library-cve-2017-17068/