The Bug

You can go past the world border by placing a boat with summon command on the middle of the border and riding it

Reproduce

• Create world on 1.18.1
• Go to 29999999 ~ ~
• Go close as possible to world border
• Use /summon minecraft:boat ~ ~2 ~ {CustomName:"Floating Boat",CustomNameVisible:1,NoGravity:1,Glowing:1}
• Ride it
• Press w to go past the world border

Observed Result

You passed the world border

Expected Result

You wouldn't pass the world border