It can depend on your precise definition of "safe". If you define it in terms of accessing correct memory, leaked memory may be inconvenient, it may be "incorre

It can depend on your precise definition of "safe". If you define it in terms of accessing correct memory, leaked memory may be inconvenient, it may be "incorrect", but it is safe. It is not, on its own, a security issue (other than eventually leading to possible program termination due to resource exhaustion, which is considered a security issue but I've always thought of this as generally "just barely" in the security class of issue). It may be chained into one if some other bug allowed access to it, but that "some other bug" would itself be the memory unsafe bug.