Has there ever been a 12–0 in the Bundesliga?

Yes, 1 time.

The only time: April 29, 1978, Borussia Mönchengladbach beat Borussia Dortmund (Borussia Mönchengladbach 12–0 Borussia Dortmund).

Nearby scores

1. 13–0 Never
2. 13–1 Never
3. 12–0 1 time
4. 12–1 Never
5. 11–0 1 time
6. 11–1 2 times