Ubuntu Security Notice USN-676-1 – It was discovered that WebKit did not properly handle Cascading Style Sheets (CSS) import statements. If a user were tricked into opening a malicious website, an attacker could cause a browser crash and possibly execute arbitrary code with user privileges.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/72219/USN-676-1.txt
Source: https://packetstormsecurity.com/files/72219/Ubuntu-Security-Notice-676-1.html