Paragraph 4. CHRIST’S FAITHFUL – HIERARCHY, LAITY, CONSECRATED LIFE

891
“The Roman Pontiff, head of the college of bishops, enjoys this
infallibility in virtue of his office, when, as supreme pastor and teacher of
all the faithful – who confirms his brethren in the faith he proclaims by a
definitive act a doctrine pertaining to faith or morals…. the infallibility
promised to the Church is also present in the body of bishops when, together
with Peter’s successor, they exercise the supreme Magisterium,” above all
in an Ecumenical Council.⁴¹⁸ When the Church through its supreme
Magisterium proposes a doctrine “for belief as being divinely
revealed,”⁴¹⁹ and as the teaching of Christ, the definitions
“must be adhered to with the obedience of faith.”⁴²⁰ This
infallibility extends as far as the deposit of divine Revelation
itself.⁴²¹

From The Catechism of the Catholic Church – rosary.team

Original Link: https://www.vatican.va/archive/ENG0015/__P2A.HTM