Auth0 Account Link Extension is an extension aimed to help link accounts easily. Versions 2.3.4 to 2.6.6 do not verify the signature of the provided JWT. This allows the user the ability to supply a forged token and the potential to access user information without proper authorization. This issue has been patched in versions 2.6.7, 2.7.0, and 3.0.0. It is recommended to upgrade to version 3.0.0 or greater.