The libpng packages contain a library of functions for creating and manipulating PNG image format files. A flaw was discovered in libpng that could result in libpng trying to free random memory if certain, unlikely error conditions occurred. If a carefully-crafted PNG file was loaded by an application linked against libpng, it could cause the application to crash or, potentially, execute arbitrary code with the privileges of the user running the application. A flaw was discovered in the way libpng handled PNG images containing "unknown" chunks. If an application linked against libpng attempted to process a malformed, unknown chunk in a malicious PNG image, it could cause the application to crash. Users of libpng and libpng10 should upgrade to these updated packages, which contain backported patches to correct these issues. All running applications using libpng or libpng10 must be restarted for the update to take effect.