Mailing the story:
Debian alert: Horde and IMP cross-site scripting attack
A cross-site scripting (CSS) problem was discovered in Horde and IMP (a web
based IMAP mail package). This was fixed upstream in Horde version 1.2.8
and IMP version 2.2.8. The relevant patches have been back-ported to
version 1.2.6-0.potato.5 of the horde package and version 2.2.6-0.potato.5
of the imp package.