Can a woman go for hajj or umrah without a mahram?

“1. When leaving her house, if she intends to travel to her mother's house and then to the other area, she will be a musaafir as the total distance which she will be traveling is 81 km (i.e. more than the safar distance). Hence, it is compulsory upon her to travel with her mahram. If she travels alone, she will be sinful.”

“In principle, it is not permissible for a woman to travel for umrah or hajj without a maḥram. This ruling applies to all women, whether young or old, and whether traveling alone or with other women.”

“A1. The Kitaabs of Fiqh state that a female is prohibited from travelling Safr distance (which is 48 miles or 78 km) without a Mahram. [Re: Fataawa Uthmaaniyyah Vol:10 Pg:107] However, in our times of Fitnah, a female should always remain with a Mahram when venturing outdoors.”

“It is not permissible for a woman to travel beyond the Sharʿī safar distance (equivalent to 48 miles) without her husband or a Maḥram (unmarriageable kin) accompanying her. Numerous authentic Aḥādīth narrated by the Ṣaḥābah affirm the prohibition of a woman travelling without a Maḥram.”