I have been wondering about this the past week or so.
My First Reconciliation, my First Communion are far in the past.
But in those days, ( imagine Grandpa Simpson's voice,) the example given when children wondered, as we inevitably did, about just how tight a seal that seal of the confessional was, we were taught, what I have since learned was basically the plot of an old movie with Montgomery Clift, don't worry, the priest can't tell anyone about it, even if he has to DIE to preserve the sancity of the confessional!
But we never thought of the confessor possibly risking something of far greater value than his life, that is - the souls of the Faithful.
Suppose a priest, or even, say a bishop, oh, what the heck, let's say a pope - suppose a pope has a confidential conversation, one that is not just pastoral, but sacramental, about the irregular situation a married woman is in, (this is all hypothetical, look you,) and he tells her something.
Now, a penitent is not bound by the seal, and let's say she tells someone who broadcasts what she has PURPORTEDLY told him on Facebook.
And his version of what was said by the confessor is a challenge to the Faith, contradicts both (immutable) doctrine and (authoritatively promulgated,) discipline; an a challenge to the Faithful, who are misled, scandalized, whatever...
Is there any way he can address this, tell the truth of what he said?
I don't think so...