Lookup is a search interface to books and dictionnaries for Emacs.
Tatsuya Kinoshita reported that the ndeb-binary function does not handle temporay files correctly.
A local attacker could use a symlink attack to overwrite files with the privileges of the user running Lookup.
There is no known workaround at this time.
All Lookup users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=app-emacs/lookup-1.4.1"