The giflib packages contain a shared library of functions for loading and saving GIF image files. This library is API and ABI compatible with libungif, the library that supported uncompressed GIF image files while the Unisys LZW patent was in effect. Several flaws were discovered in the way giflib decodes GIF images. An attacker could create a carefully crafted GIF image that could cause an application using giflib to crash or, possibly, execute arbitrary code when opened by a victim. All users of giflib are advised to upgrade to these updated packages, which contain backported patches to resolve these issues. All running applications using giflib must be restarted for the update to take effect.