Ubuntu has released a number of patches for security vulnerabilities in several versions of the OS. Thunderbird is Mozilla s email client, and the company recently fixed several memory corruption vulnerabilities, along with a cross-site request forgery bug and a flaw that could lead to a session-fixation attack. In addition to the Thunderbird vulnerabilities, there are also patches for several other flaws in Ubuntu. One of the patches fixes a bug in libssh that could cause a denial of service.
Source: https://threatpost.com/ubuntu-patches-several-security-flaws/110550/