Jami` at-Tirmidhi 1102
جامع الترمذي#1102SahihAishah narrated that:The Messenger of Allah said: "Whichever woman married without the permission of her Wali her marriage is invalid, her marriage is invalid, her marriage is invalid. If he entered into her, then the Mahr is for her in lieu of what he enjoyed from her private part. If they disagree, then the Sultan is the Wali for one who has no Wali
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Zubair Ali ZaiIsnaad Sahih
In-book reference: 11:23