Entity Selectors

Hey Mojang , so i found this bug
I was in peaceful and i tried the new command of
@e
and I combined it with /effect @p 8 2 10
(So the mobs near can have jump boost)
And when i tried this , it effected all mobs that were not even there such as
Slime's that are not available for peaceful .
I cant really put a screenshot because the chat is spammed and you cant see the difficulty 0 but if you try it out its better ,
Thanks for reading!