Learn Spanish (Latin America): Ayer se confirmó que hubo una infidelidad en el palacio. - Yesterday it was confirmed that there was an infidelity in the palace.

The verb confirmar (to confirm) declares a fact or a certainty. When we use the structure se confirmó que (it was confirmed that), we are reporting what happened rather than expressing doubt, emotion, or a subjective opinion. Because it's a declaration of a fact, the following clause uses the indicative.

Why use the preterite hubo instead of the imperfect había for "there was"?

We use hubo when "there was" refers to a specific, completed event or incident. In this sentence, the infidelity is being treated as a single occurrence that took place and concluded, rather than continuous, descriptive background information (which would require había).

Could I say Ayer fue confirmado que... instead of Ayer se confirmó que...?

Grammatically yes, and you might see fue confirmado in formal news reports or translated texts. However, using the impersonal se structure is much more natural and common in everyday Spanish when you want to say "it was [verb]ed" without naming a specific subject.

Is infidelidad the usual word for cheating in a relationship?

Yes, infidelidad is standard, widely used, and understood everywhere. In casual conversation, you might also hear the informal idiom poner los cuernos (literally "to put the horns" on someone) to describe cheating.