A temporary exemption for Fannie Mae and Freddie Mac mortgages is among the plethora of provisions contained within the Consumer Financial Protection Bureaus long-awaited qualified mortgage rule issued last week. Even so, credit unions fear onerous GSE buyback requirements may be an unintended consequence of the new rule.Called for by the Dodd-Frank Act, the CFPBs QM rule lists the characteristics of a qualified mortgage, or one that regulators will presume will be within a borrowers ability to repay the loan.