Ask HN: How best to disclose paywall loophole?

Background: I'm an amateur coder at best but a solid base in my teens helped me get off the ground. That said, I often putz around on random sites.

Issue/Discovery: A reasonably sized media company who has a paywall for certain content came across my screen recently. I explored the coding for the paywalled site and discovered the content was clearly available in the coding with some basic unicode cleanup needed. To test my skills I wrote a quick script and proved that I could pull the content for any of the "protected" pages.

Question: How do I best disclose the issue without getting into any trouble for discovering it? I want to be sure the hole is closed as I want them to succeed.