Auth0 is an authentication broker that supports both social and enterprise identity providers, including Active Directory, LDAP, Google Apps, and Salesforce. In versions before `11.33.0`, when the “additional signup fields” feature [is configured](https://github.com/auth0/lock#additional-sign-up-fields), a malicious actor can inject invalidated HTML code into these additional fields, which is then stored in the service `user_metdata` payload (using the `name` property). Verification emails, when applicable, are generated using this metadata. It is therefor possible for an actor to craft a malicious link by injecting HTML, which is then rendered as the recipient's name within the delivered email template. You are impacted by this vulnerability if you are using `auth0-lock` version `11.32.2` or lower and are using the “additional signup fields” feature in your application. Upgrade to version `11.33.0`.

auth0-lock is Auth0's signin solution. Versions of nauth0-lock before and including `11.30.0` are vulnerable to reflected XSS. An attacker can execute arbitrary code when the library's `flashMessage` feature is utilized and user input or data from URL parameters is incorporated into the `flashMessage` or the library's `languageDictionary` feature is utilized and user input or data from URL parameters is incorporated into the `languageDictionary`. The vulnerability is patched in version 11.30.1.

In auth0-lock versions before and including 11.25.1, dangerouslySetInnerHTML is used to update the DOM. When dangerouslySetInnerHTML is used, the application and its users might be exposed to cross-site scripting (XSS) attacks.

Auth0 Lock before 11.21.0 allows XSS when additionalSignUpFields is used with an untrusted placeholder.