libxml is a library for parsing and manipulating XML files. A Document Type Definition defines the legal syntax for certain types of files, such as XML files. A stack overflow flaw was found in the way libxml processes the root XML document element definition in a DTD. A remote attacker could provide a specially-crafted XML file, which once opened by a local, unsuspecting user, would lead to denial of service . Multiple use-after-free flaws were found in the way libxml parses the Notation and Enumeration attribute types. A remote attacker could provide a specially-crafted XML file, which once opened by a local, unsuspecting user, would lead to denial of service . Users should upgrade to these updated packages, which contain backported patches to resolve these issues. For Red Hat Enterprise Linux 3, they contain backported patches for the libxml and libxml2 packages. For Red Hat Enterprise Linux 4 and 5, they contain backported patches for the libxml2 packages. The desktop must be restarted for this update to take effect.