In which countries is cheating in university exams considered a crime?

In Italy cheating in a public university can be punished with 3-12 months of imprisonment.

The relevant law is almost one century old, but it is still valid today.

From https://www.normattiva.it/uri-res/N2Ls?urn:nir:stato:legge:1925-04-19;475 :

LEGGE 19 aprile 1925, n. 475

Art. 1 Chiunque in esami o concorsi, prescritti o richiesti da autorita' o pubbliche Amministrazioni per il conferimento di lauree o di ogni altro grado o titolo scolastico o accademico, per l'abilitazione all'insegnamento od all'esercizio di una professione, per il rilascio di diplomi o patenti, presenta, come propri, dissertazioni, studi, pubblicazioni, progetti tecnici e, in genere, lavori che siano opera di altri, e' punito con la reclusione da tre mesi ad un anno. La pena della reclusione non puo' essere inferiore a sei mesi qualora l'intento sia conseguito.

My attempt at a translation (excuse the convoluted 1925 Italian syntax).

Law no. 475, April 19 1925.

Article 1: whoever presents as his/her own a study, dissertation, publication, technical project, or, generically, a work that is made by someone else, in an exam or selection, prescribed or requested by authorities or by the public administration to confer degrees or any other sort of academic or school qualifications, or for habilitation to the practice of a profession or to teaching, is to be punished with imprisonment from 3 months up to one year. This penalty cannot be lower than six months when the attempt is successful.

In Canada there is a section of the Criminal Code (equivalent to US Federal law; but there are no Provincial "criminal" laws) called "Personation at examination" that deals exactly with this:

404 Every one who falsely, with intent to gain advantage for himself or some other person, personates a candidate at a competitive or qualifying examination held under the authority of law or in connection with a university, college or school or who knowingly avails himself of the results of such personation is guilty of an offence punishable on summary conviction.

And yes, it's been used: There was a case in 2014 in which a forged identity document was allegedly used to allow a PhD-level student to write an undergrad's exam for hire. This resulted in charges reported as "uttering forged documents" as well as the one above. Note that as the law is worded, both the actor and the willing subject of the "personation" can be charged under the same section.

("Personation" seems to be an archaic form used in law; it's not a widespread Canadianism for "impersonation".)

In France, see the law of December 23, 1901 related to fraud at exams.

You risk 3 years of jail by cheating at exams. Even at the Baccalauréat (end of high school at age of about 18), or competitive exams for entrance at any Grande École (some of which, including Écoles normales supérieures or École Polytechnique, giving you a civil servant status and pay when studying there; I was very happy to be graduated from ENS Cachan and paid there, with the contractual obligation to serve the State for ten years or else reimburse part of my salary as student & civil servant).

I am not a lawyer, so I don't know how often is that law applicable in practice.

But you certainly forbid yourself from any State related employment (so hospitals, army, police, research, education, law, defense or space industry, or even Airbus ....) if you are condemned for cheating. AFAIK, cheating at Baccalauréat (and been caught) forbids you to go to University for several years, and could be written on your criminal record ("casier judiciaire").

I made nearly all my career at CEA and I would be forbidden to be hired (in 1985) if I ever cheated at exams.

I taught and gave exams at University, and cheating is a very serious thing there. Anyone teaching at university and permitting (on purpose) fraud would have a lot of trouble (similar to some kind of sexual harassment on students).