CVE 2009-4371

Cross-site scripting (XSS) vulnerability in the Locale module (modules/locale/locale.module) in Drupal Core 6.14, and possibly other versions including 6.15, allows remote authenticated users with "administer languages" permissions to inject arbitrary web script or HTML via the (1) Language name in English or (2) Native language name fields in the Custom language form.

See the CVE page on Mitre.org for more details.