A CSS injection vulnerability has been discovered on GitHub, allowing users to customize their profiles in unintended ways. The vulnerability, involving MathJax, was initially found by @cloud11665 and later confirmed by other security researchers. This flaw enables users to inject CSS code into their profiles, leading to creative customizations and potential security risks. For instance, researchers have shown that the vulnerability can be exploited to create ReadMe files that log users out of their profiles or even capture their IP addresses. GitHub is now facing scrutiny as the platform has become a playground for such exploits.