In Octopus Deploy before 4.1.3, the machine update process doesn't check that the user has access to all environments. This allows an access-control bypass because the set of environments to which a machine is scoped may include environments in which the user lacks access.
Octopus before 3.17.7 allows attackers to obtain sensitive cleartext information by reading a variable JSON file in certain situations involving Offline Drop Targets.
An issue was discovered in Octopus before 3.17.7. When the special Guest user account is granted the CertificateExportPrivateKey permission, and Guest Access is enabled for the Octopus Server, an attacker can sign in as the Guest account and export Certificates managed by Octopus, including the private key.
In Octopus before 3.17.7, an authenticated user who was explicitly granted the permission to invite new users (aka UserInvite) can invite users to teams with escalated privileges.