According to the Guardian https://www.theguardian.com/us-news/live/2026/mar/01/us-israel-war-on-iran-ayatollah-ali-khamenei-i-dead-latest-reports "More details are emerging on who will lead Iran during a transition period, following Khamenei’s death. Iranian President Masoud Pezeshkian, Judiciary chief Gholamhossein Mohseni Ejei and another official from the country’s legal council will be part of the trio overseeing the transition, according to state television which cited Mohammad Mokhber, one of Khamenei’s advisors. Last summer during the 12-day war with Israel, Khamenei named three potential successors should he be killed. Reports earlier this month indicated that Khamenei had named four layers of succession for key government and military jobs, in an effort to ensure regime survival in the face of a US-Israeli attack."