ldebug.c in Lua 5.4.0 allows a negation overflow and segmentation fault in getlocal and setlocal, as demonstrated by getlocal(3,2^31).
Buffer overflow in the vararg functions in ldo.c in Lua 5.1 through 5.2.x before 5.2.3 allows context-dependent attackers to cause a denial of service (crash) via a small number of arguments to a function with a large number of fixed arguments.