The 'mise' tool versions from 2026.3.15 up to but not including 2026.6.4 allow local project configuration files (.mise.toml) to specify a 'github.credential_command' that is executed without trust validation. This enables an attacker who can place a malicious .mise.toml in a repository to execute arbitrary shell commands as the victim user when the victim runs a GitHub-related mise command and no higher-priority GitHub token environment variable is set. The vulnerability is fixed in version 2026.6.4.