Umbraco, a free and open source .NET content management system, has a remote code execution issue in versions on the 13.x branch prior to 13.5.2, 10.x prior to 10.8.7, and 8.x prior to 8.18.15. There is a potential risk of code execution for Backoffice users when they “preview” SVG files in full screen mode. Versions 13.5.2, 10.8,7, and 8.18.15 contain a patch for the issue. As a workaround, derver-side file validation is available to strip script tags from file's content during the file upload process.

Umbraco has a Potential Code Execution Risk When Viewing SVG Files in Full Screen in Backoffice