LTI JupyterHub Authenticator does not properly validate JWT Signature
Only users that has configured a JupyterHub installation to use the authenticator class LTI13Authenticator are influenced. LTI13Authenticator that was introduced in jupyterhub-ltiauthenticator 1.3.0 wasn't validating JWT signatures. This is believed to allow the LTI13Authenticator to authorize a forged request granting access to existing and new user identities.