CVE-2018-18850
In Octopus Deploy 2018.8.0 through 2018.9.x before 2018.9.1, an authenticated user with permission to modify deployment processes could upload a maliciously crafted YAML configuration, potentially allowing for remote execution of arbitrary code, running in the same context as the Octopus Server (for self-hosted installations by default, SYSTEM).
Source: CVE-2018-18850