New vulnerabilities were found in the Linux 3.2 and 3.5 kernels, which power the Ubuntu 12.04 LTS (Precise Pangolin) and Ubuntu 12.10 (Quantal Quetzal) operating systems, and Canonical just issued patches for them.
The following four Linux kernel vulnerabilities affect Ubuntu 12.04 LTS (Precise Pangolin) and Ubuntu 12.10 (Quantal Quetzal): CVE-2013-0190, CVE-2013-0216, CVE-2013-0217, CVE-2013-0228, CVE-2013-0231, CVE-2013-0268, CVE-2013-0311, CVE-2013-0313, CVE-2013-0349 and CVE-2013-1774.
The security flaws can be fixed if you upgrade your system(s) to the linux-image-3.2.0-39 (3.2.0-39.62) package(s) for Ubuntu 12.04 LTS, and the linux-image-3.5.0-26 (3.5.0-26.42) package(s) for Ubuntu 12.10.
For detailed instructions on how to upgrade your system, see the following link: https://wiki.ubuntu.com/Security/Upgrades. Don't forget to reboot your computer after the upgrade!