Carry-on Baggage - Vietnam Airlines

What the official page says

You are allowed one piece of carry-on baggage with maximum dimensions 56 x 36 x 23 cm (total linear dimensions not exceeding 115 cm) plus one accessory item (40 x 30 x 15 cm, total linear under 85 cm). For tickets issued from 5 May 2025 on flights to/from the US, Europe and Australia, Economy passengers may carry 1 cabin bag + 1 accessory with total weight not exceeding 12 kg (each piece up to 10 kg); Business and Premium passengers may carry 2 cabin bags + 1 accessory up to 18 kg. On other routes Economy allows 1 cabin bag + 1 accessory up to 10 kg.