When Edebug is entered and actually reads commands from the user, it saves (and later restores) these additional data:
track-mouse. Commands in Edebug do not affect these variables outside of Edebug.
Executing commands within Edebug can change the key sequence that
would be returned by
this-command-keys, and there is no way to
reset the key sequence from Lisp.
Edebug cannot save and restore the value of unread-command-events. Entering Edebug while this variable has a nontrivial value can interfere with execution of the program you are debugging.
command-history. In rare cases this can alter execution.
recursive-edit, but Edebug temporarily restores them during evaluations.
defining-kbd-macrois bound to