Player can fly in Creative mode using only jump and sneak keys without any items or commands

Description:

In Creative mode the player entity ignores gravity and obtains full flight without any item, command or third-party tool. Tested on a clean vanilla installation.

Steps to reproduce:

Launch Minecraft 26.3 and create a new single-player world in Creative mode.

Stand on any solid block.

Hold jump (Space) and observe continuous vertical ascent.

Release jump and observe the player remains suspended with no fall.

Hold sneak (Shift) and observe smooth controlled descent.

Use W/A/S/D and mouse to move horizontally in all directions while airborne.

Confirm no hunger, stamina or resource is consumed.

Expected result:

The player should remain affected by gravity and should not sustain aerial movement without flight-enabling items (for example Elytra, fireworks) or commands (for example /gamemode). In Creative mode, if flight is intentional, it should be explicitly governed by capability flags rather than triggered by basic jump input alone.

Actual result:

Holding jump produces unlimited ascent; with no input the player hovers indefinitely; sneak produces full descent control; horizontal flight works in every direction; effective gravity is approximately 0 m/s²; no resource cost occurs. Reproduced 100% across reloads and different seeds.