Fixed bug that allowed a hovercard URL to be used to display the name, description, and star count of any repository

On March 30, 2023, we fixed a bug that allowed a dependency graph hovercard URL to be used to retrieve the name, description, and star count of any repository on GitHub.com. The bug was introduced on March 28, 2023 and our investigation has found no evidence of exploitation. To exploit the bug, a specific header needed to be set when making a request to the URL and the numeric ID of a repository provided. The URL would then return the HTML content designed to be used for a hovercard UI element with the repository name, description, and star count in the response.

This bug was reported to GitHub via the GitHub Bug Bounty program.