Possibly. You are correct. The employee portion of social security tax is 6.2%. Try deleting the W-2 and re-adding it to correct this entry. 

To do this in TurboTax, return to the input screen and follow these steps:

• By the W-2 in question, select the trash can icon to Delete the Form.
• To add a W-2, select Add W-2 in the lower left area of the input screen.

For more information, see: How do I import or enter my W-2?

You entered $4,866.52 in box 3 of TurboTax's W-2 form instead of $48,660.52.  Go back and correct that entry.