OpenAI Codex Desktop for Windows and macOS automatically inspected Git metadata and working-tree status when a user opened a workspace. If the workspace contains a repository with preserved attacker-controlled .git/config, the attr.tree setting and a configured clean or process filter can cause Git to run an attacker-controlled program. The program runs outside Codex's command sandbox with the signed-in user's privileges, without a workspace-trust prompt, command approval, or interaction with a model. The attacker can read, modify, or delete files and access credentials available to that user. Exploitation requires Git to be available on PATH and the user to open the attacker-prepared repository with its local Git configuration intact. An ordinary Git clone does not copy the source repository's .git/config and is not sufficient by itself.