"Senza né" is not really acceptable in modern Italian because it's a double negation. Treccani Encyclopedia only mentions "senza A né B". Linguist Massimo Arcangeli is of the opinion that, although "senza né A né B" is accepted in poetry and literature, it should be avoided. Note that archaic forms like "senza neanche", "senza neppure", "senza nemmeno" or "senza nemmanco" are widely accepted. In modern spoken Italian, "senza né A né B" is usually pronounced with a short pause after "senza" and accompanied by a mimic gesture of the fingers counting the two alternatives, A and B (and possibly others).
According to Treccani dictionary:
«5. Quando si escludono due cose, la congiunzione correlativa a senza
è né, più raram. o: lo tennero in cella tre giorni, s. mangiare né
bere; è uno strozzino, s. pietà né riguardo per nessuno (meno spesso,
s. pietà o riguardo).»
So it would be either "senza A né B" or "senza A o B".
They have been talking about it here as well.
I think this is an interesting question indeed - it would be nice to read other linguists' point of view.