template<typename Container, typename Value>
    hash_map_iterator<Container,Value>::hash_map_iterator( const Container &map, size_t index, const bucket *b, node_base *n ) :
        my_map(&map),
        my_index(index),
        my_bucket(b),
        my_node( static_cast<node*>(n) )          // <-- UB static_cast to node*, as n is 0x3. It is not an 8-byte aligned address.
    {
        if( b && !hash_map_base::is_valid(n) )
            advance_to_next_bucket();
    }

SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior /path_to_tbb/tbb/2020.3/include/tbb/concurrent_hash_map.h:442:18 in 
/path_to_tbb/tbb/2020.3/include/tbb/concurrent_hash_map.h:377:27: runtime error: downcast of misaligned address 0x000000000003 for type 'tbb::interface5::internal::hash_map_iterator<tbb::interface5::concurrent_hash_map<int, int>, std::pair<const int, int>>::node' (aka 'tbb::interface5::concurrent_hash_map<int, int>::node'), which requires 8 byte alignment
0x000000000003: note: pointer points here

#include <tbb/concurrent_hash_map.h>

int
main()
{
  tbb::concurrent_hash_map<int, int> map;

  map.insert({0, 0});
  auto r = map.range();

  return 0;
}

hash_map_iterator(const HashMapType& map,
                                                                    size_t             index,
                                                                    const bucket*      b,
                                                                    node_base*         n)
    : my_map(&map), my_index(index), my_bucket(b), my_node(nullptr) {
    if (b) {
        if (!hash_map_base::is_valid(n))
            advance_to_next_bucket();
        else
            my_node = static_cast<node*>(n);
    }
}