The libpng packages contain a library of functions for creating and manipulating PNG image format files. A heap-based buffer overflow flaw was found in the way libpng processed tEXt chunks in PNG image files. An attacker could create a specially-crafted PNG image file that, when opened, could cause an application using libpng to crash or, possibly, execute arbitrary code with the privileges of the user running the application. Users of libpng should upgrade to these updated packages, which correct this issue. For Red Hat Enterprise Linux 5, they contain a backported patch. For Red Hat Enterprise Linux 6, they upgrade libpng to version 1.2.49. All running applications using libpng must be restarted for the update to take effect.