The read_scalar and read_scalar_at functions are unsound because they allow transmuting values without unsafe blocks.

The following example shows how to create a dangling reference:

fn main() {
    #[derive(Copy, Clone, PartialEq, Debug)]
    struct S(&'static str);
    impl flatbuffers::EndianScalar for S {
        fn to_little_endian(self) -> Self { self }
        fn from_little_endian(self) -> Self { self }
    }
    println!("{:?}", flatbuffers::read_scalar::<S>(&[1; std::mem::size_of::<S>()]));
}

Code generated by flatbuffers' compiler is unsafe but not marked as such. See https://github.com/google/flatbuffers/issues/6627 for details.

For example, if generated code is used to decode malformed or untrusted input, undefined behavior (and thus security vulnerabilities) is possible even without the use of the unsafe keyword, violating the the meaning of "safe" code;

All users that use generated code by flatbuffers compiler are recommended to:

1. not expose flatbuffer generated code as part of their public APIs
2. audit their code and look for any usage of follow, push, or any method that uses them (e.g. self_follow).
3. Carefully go through the crates' documentation to understand which "safe" APIs are not intended to be used.