Ubuntu Security Notice 960-1 – It was discovered that libpng did not properly handle certain malformed PNG images. If a user or automated system were tricked into opening a crafted PNG file, an attacker could cause a denial of service or possibly execute arbitrary code with the privileges of the user invoking the program. It was discovered that libpng did not properly handle certain malformed PNG images. If a user or automated system were tricked into processing a crafted PNG image, an attacker could possibly use this flaw to consume all available resources, resulting in a denial of service.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/91619/USN-960-1.txt
Source: https://packetstormsecurity.com/files/91619/Ubuntu-Security-Notice-960-1.html