Expat is a C library written by James Clark for parsing XML documents.
Two buffer over-read flaws were found in the way Expat handled malformed UTF-8 sequences when processing XML files. A specially-crafted XML file could cause applications using Expat to crash while parsing the file. (CVE-2009-3560, CVE-2009-3720)
All expat users should upgrade to these updated packages, which contain backported patches to correct these issues. After installing the updated packages, applications using the Expat library must be restarted for the update to take effect.