Ubuntu Security Notice 844-1 – Chris Evans discovered that mimeTeX incorrectly handled certain long tags. An attacker could exploit this with a crafted mimeTeX expression and cause a denial of service or possibly execute arbitrary code. Chris Evans discovered that mimeTeX contained certain directives that may be unsuitable for handling untrusted user input. This update fixed the issue by disabling the input and counter tags.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/81875/USN-844-1.txt
Source: https://packetstormsecurity.com/files/81875/Ubuntu-Security-Notice-844-1.html