Is it possible to edit $_SESSION by hacker?

[Khloe_Kansas]

I save some important info in \[code\]$_SESSION\[/code\], not in \[code\]$_COOKIE\[/code\]. So, my question, is it dangerous? Or hacker is not able to edit \[code\]$_SESSION\[/code\] and I'm fine?Thank you.edited:By the way, is it possible also to edit \[code\]$_COOKIE\[/code\]? I heard yes, but if yes, then how?