TurboTax would need your consent before sharing tax information with any of its partners. Tax information is shared when you select some services such as a refund advance loan, paying your tax fees with your federal refund or have your money deposited in a Credit Karma Money account. That consent is optional just for those purposes.
Limiting your offers to only what you need means TurboTax will only share info when absolutely necessary to file your return the way you want.
In order to file electronically with TurboTax Online, you are asked to agree to the INTUIT TERMS OF SERVICE FOR TURBOTAX ONLINE TAX PREPARATION SERVICES. See here for the complete licensing agreement. See here for the Global Privacy Statement.
TurboTax needs to be able to share your data electronically with the IRS and State agencies in order to file your return.
As always, TurboTax will not share your tax preparation data without your explicit consent, as required by law.
See here for information regarding TurboTax Data Security.