Bootrom 5756.0.0.100.52

From The Apple Wiki

Bootrom for the M1 Pro, M1 Max, and M1 Ultra, which were used in the MacBook Pro (14-inch, 2021), MacBook Pro (16-inch, 2021), and the Mac Studio (2022).

This bootrom has no known vulnerabilities and was compiled before iOS 14.0 beta.