Please do not open a public issue for security vulnerabilities.
Instead, report them privately via GitHub's security advisories ("Report a vulnerability"). You will receive a response as soon as possible, and disclosure will be coordinated with you.
munpae programs DNS records in a backend using credentials you supply (TSIG keys, a Cloudflare API token, or a webhook endpoint) via environment variables. Keep those secrets out of version control and restrict them to the minimum required permissions (e.g. a Cloudflare token scoped to the managed zone).