Infallible teaching

I asked this question earliermay, and may not have posted in the right thread. Is the Catholic teaching on the unforgivable sin considered infallible? Is it a teaching of the magisterium that all sins can be forgiven if repented?

Yes and yes.

What specifically is the unforgivable sin?

DISCLAIMER: The views and opinions expressed in these forums do not necessarily reflect those of Catholic Answers. For official apologetics resources please visit www.catholic.com.