The confidentiality of confession is among the strongest secrecy obligations any institution places on its members, and it is currently under sustained pressure.
Catholic canon law makes the seal absolute. A priest may not reveal what he hears in confession for any reason whatever, including to prevent a crime, and breaking it incurs automatic excommunication reserved to Rome. There is no exception for grave crime, for a court order, or for the safety of a child. Priests have gone to prison rather than testify, and the church regards that as the correct outcome.
The pressure comes from child abuse inquiries. Australia's royal commission recommended in 2017 that clergy be required to report abuse disclosed in confession, and several Australian jurisdictions legislated to that effect; comparable proposals have been made in other countries since. The church's position has not moved, and bishops have stated publicly that priests will accept imprisonment rather than comply. Both positions are held sincerely, and neither has an obvious answer. The argument that the seal is what makes any disclosure possible in the first place is not frivolous. Nor is the observation that in practice it has protected offenders.
Other traditions meet the question in different shapes because they organise the practice differently. Protestant clergy are generally covered by a narrower statutory privilege that varies by jurisdiction and often carries explicit exceptions. Where confession is communal, or made directly to God without a human hearer, the problem does not arise in this form at all. That is not an accident of history so much as a consequence of who is standing there, and it is one of the clearest cases where the mechanics of a practice generate its legal difficulties.