Created Unassigned: Cross-Site Scripting (Insufficient Entropy (CWE ID 331) issues in ColsedXml.dll [9386]

We are using ColsedXml.dll In our application. We are mandated by our organization to scan our code in Veracode Site for security scan. While running the scan we got __"Cross site scripting flaws in ColsedXml.dll"__
Please advise to fix/overcome these flaws.

__Issues Details:

Cross-Site Scripting - Insufficient Entropy (CWE ID 331) - Cryptographic Issues

Module: ClosedXML.dll (Product Version 0.69.1.0)__

1) In closedxml_dll.
File name : ClosedXML.Excel.CalcEngine.MathTrig
Method Name : RandBetween

2) In closedxml_dll.
File name : ClosedXML.Excel.CalcEngine.MathTrig
Method Name : Rand