Drupal 5.x before 5.13 and 6.x before 6.7 does not delete all related content when an input format is deleted, which prevents the content from being properly filtered and allows remote attackers to conduct cross-site scripting (XSS) attacks via unspecified vectors.
drupal.org/node/345441
secunia.com/advisories/33112
secunia.com/advisories/33147
www.osvdb.org/50662
www.vupen.com/english/advisories/2008/3414
exchange.xforce.ibmcloud.com/vulnerabilities/47259
www.redhat.com/archives/fedora-package-announce/2008-December/msg00740.html
www.redhat.com/archives/fedora-package-announce/2008-December/msg00767.html