https://rhn.redhat.com/errata/RHSA-2005-176.html refers: This update has been rated as having critical security impact by the CentOS Security Response Team. The following updated file has been uploaded and is currently syncing to the mirrors: firefox-1.0.1-1.4.3.centos4.1.i386.rpm You may update you CentOS-4 i386 installations by running the command: yum upgrade Thanks Johnny Hughes