The New Zealand captain was sent off after making direct contact with the head of South Africa centre Jesse Kriel in a first-half tackle.
Cane was initially shown a yellow card but the sanction was upgraded on review in the TMO bunker, leaving the All Blacks without their openside flanker for most of the final as the Springboks secured back-to-back triumphs.
And a World Rugby disciplinary hearing has now levied a three-match ban, likely to be reduced to two on the completion of the World Rugby Coaching Intervention Programme, known informally as “tackle school”.
Cane accepted that he had committed an act of foul play but challenged the officials’ decision that the incident merited a red card, arguing he should only have been sin-binned.
However, the disciplinary committee panel upheld the red card, setting a mid-range entry point of six weeks.
The ban is reduced to three weeks on account of Cane’s acknowledgement of the offence, remorse shown at the hearing and previously exemplary disciplinary record.
The 31-year-old will return in June of next year and be available for international selection ahead of the 2024 Rugby Championship.
“It’s hard to find the words to explain it,” Cane said after his side fell short in Paris last month. “It’s hard because I’m feeling so much hurt but proud because of the way we fought back.
“It speaks volumes of the group as a whole. A fantastic group of men who care so much about the All Blacks. There’s a lot of heartbreak in the shed and it’s hard. It’s something, unfortunately, I’m going to have to live with forever.”