Sahih al-Bukhari 1088
صحيح البخاري#1088SahihNarrated Abu Huraira:The Prophet (ﷺ) said, "It is not permissible for a woman who believes in Allah and the Last Day to travel for one day and night except with a Mahram
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 18:9