OpenAC is a game client that talks to a game server over UDP and reads data files you supply. If you find a way to make it execute code, read files it should not, or misbehave against a server in a way that affects other players, please report it privately.
Open a private report at https://github.com/eriknihlen/OpenAC/security/advisories/new. Include the version (from the launcher), the steps, and what you observed. You will get an acknowledgement within a week.
Please do not open a public issue for a security problem until a fix has shipped.
In scope: the client, the launcher and updater, the headless host, and the plugin loader. Out of scope: the game servers you connect to, and the retail data files.