When killing the smallest magma cubes, they will still inflict damage the player after they have died if you walk over them during their death animation.
Edit by @unknown: This bug occurs with all magma cube sizes, as well as all sizes of slimes, except for the smallest size, since the smallest slimes don't inflict any damage anyway. The damage caused by the magma cubes/slimes is likely due to the unique way in which slimes/magma cubes deal damage to the player. In the Java edition, slimes deal damage whenever the player's hitbox collides with their own... if MCPE slimes & magma cubes are coded similarly, then this behavior is probably related to this bug.
Linked issues
is cloned by 1
is duplicated by 2
relates to 1
Attachments
Comments 10
Relates to MCPE-9999
clean-
Still affects 0.15.1 - Have added a video to help show the bug.

Revised title to reflect the fact that this bug affects slimes as well. (Though keep in mind that it doesn't affect the smallest size of slime, since those don't deal damage anyway.)
Affects 1.5.0.7 on windows 10.
Still affects 1.6.0.5
Still affects 1.6.0.6
Still affects 1.6.0.8
Fixed in an earlier version.
Confirmed on Samsung Galaxy S6 (SM-G920W8), Android 5.1.1 in single player survival.