XI. The Celebration of the Sacrament of Penance

1483
In
case of grave necessity recourse may be had to a communal celebration of
reconciliation with general confession and general absolution. Grave necessity
of this sort can arise when there is imminent danger of death without
sufficient time for the priest or priests to hear each penitent’s confession.
Grave necessity can also exist when, given the number of penitents, there are
not enough confessors to hear individual confessions properly in a reasonable
time, so that the penitents through no fault of their own would be deprived of
sacramental grace or Holy Communion for a long time. In this case, for the
absolution to be valid the faithful must have the intention of individually
confessing their sins in the time required.⁹¹ The diocesan bishop is
the judge of whether or not the conditions required for general absolution
exist.⁹² A large gathering of the faithful on the occasion of major
feasts or pilgrimages does not constitute a case of grave necessity.⁹³

From The Catechism of the Catholic Church – rosary.team

Original Link: https://www.vatican.va/archive/ENG0015/__P4H.HTM