Secunia Security Advisory – Ubuntu has issued an update for libpng. This fixes two vulnerabilities, which can be exploited by malicious people to cause a DoS (Denial of Service) and potentially compromise an application using the library.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/91609/sa40472.txt
Source: https://packetstormsecurity.com/files/91609/Secunia-Security-Advisory-40472.html