Microsoft .NET Framework 2.0 SP2, 3.5, 3.5.1, 4.5.2, 4.6, and 4.6.1 does not prevent recursive compilation of XSLT transforms, which allows remote attackers to cause a denial of service (performance degradation) via crafted XSLT data, aka ".NET Framework Stack Overflow Denial of Service Vulnerability."
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2016/ms16-019