The email address they have listed there is defunct, and they haven't bothered to update this security.txt page. When you try emailing disclosure@openai.com, you get an auto-reply saying:

    Hello and thank you for reaching out to OpenAI. Our vulnerability disclosure program has migrated to OpenAI's bug bounty program, and this mailbox is no longer monitored. Please use the "submit report" functionality available through our bug bounty platform to inform us of security concerns, or reach out to support@openai.com for any non-security-related inquiries.

    Thank you for your help in securing OpenAI!

    Bug Bounty Program: https://bugcrowd.com/openai