CVE-2020-26250

OAuthenticator is an OAuth login mechanism for JupyterHub. In oauthenticator from version 0.12.0 and before 0.12.2, the deprecated (in jupyterhub 1.2) configuration Authenticator.whitelist, which should be transparently mapped to Authenticator.allowed_users with a warning, is instead ignored by OAuthenticator classes, resulting in the same behavior as if this configuration has not been set. If this is the only mechanism of authorization restriction (i.e. no group or team restrictions in configuration) then all authenticated users will be allowed. Provider-based restrictions, including deprecated values such as GitHubOAuthenticator.org_whitelist are not affected. All users of OAuthenticator 0.12.0 and 0.12.1 with JupyterHub 1.2 (JupyterHub Helm chart 0.10.0-0.10.5) who use the admin.whitelist.users configuration in the jupyterhub helm chart or the c.Authenticator.whitelist configuration directly. Users of other deprecated configuration, e.g. `c.GitHubOAuthenticator.team_wh