A vulnerability has been discovered and corrected in mono: Cross-site scripting vulnerability in the ProcessRequest function in mcs/class/System.Web/System.Web/HttpForbiddenHandler.cs in Mono 2.10.8 and earlier allows remote attackers to inject arbitrary web script or HTML via a file with a crafted name and a forbidden extension, which is not properly handled in an error message . The updated packages have been patched to correct this issue.