Reference: Sitefinity CMS and .NET framework compatibility
The following article lists the compatibility of Sitefinity CMS releases with Microsoft .NET framework versions.
    
    
        
            | Sitefinity CMS release | 
            .NET framework | 
        
        
            | 12.0 to 13.1 | 
            4.7.2 | 
        
        
            | 11.0 to 11.2 | 
            4.7.1 | 
        
        
            | 10.0 to 10.2 | 
            4.5 | 
        
        
            | 4.0 to 10.0 | 
            4.0 | 
        
    
 IMPORTANT: Before upgrading your Sitefinity CMS, you must install the Microsoft .NET framework version that is compatible with the new Sitefinity CMS release.