The libpng package contains a library of functions for creating and manipulating PNG (Portable Network Graphics) image format files.
A heap based buffer overflow bug was found in the way libpng strips alpha channels from a PNG image. An attacker could create a carefully crafted PNG image file in such a way that it could cause an application linked with libpng to crash or execute arbitrary code when the file is opened by a victim. The Common Vulnerabilities and Exposures project has assigned the name CVE-2006-0481 to this issue.
Please note that the vunerable libpng function is only used by TeTeX and XEmacs on Red Hat Enterprise Linux 4.
All users of libpng are advised to update to these updated packages which contain a backported patch that is not vulnerable to this issue.