NuGetGallery's Markdown Autolinks Processing Vulnerable to Cross-site Scripting

NuGet Gallery is a package repository that powers nuget.org. The NuGetGallery has a security vulnerability related to its handling of autolinks in Markdown content. While the platform properly filters out JavaScript from standard links, it does not adequately sanitize autolinks. This oversight allows attackers to exploit autolinks as a vector for Cross-Site Scripting (XSS) attacks. When a user inputs a Markdown autolink such as <javascript:alert(1)>, the link is rendered without proper sanitization. This means that the JavaScript code within the autolink can be executed by the browser, leading to an XSS attack. Version 2024.05.28 contains a patch for this issue.