Check out new fixes in Claris FileMaker Server 19.3.3
Claris FIleMaker Server 19.3.3 disables external entity resolution during import from Excel so that external DTDs are no longer processed.
See the release notes for more details.
FileMaker Server 19.3.3 is available as a full installer, which can also upgrade or update an existing installation. Download the installer from your Electronic Software Download (ESD) page or from Claris Customer Console. For further information, see FileMaker Server Help or visit the support resources on the Claris website.