Canonical announced a few minutes ago, May 8th, in a security notice, that a new Linux kernel update for its Ubuntu 11.04 (Natty Narwhal) operating system is now live. The update fixes three security vulnerabilities discovered in the Linux 2.6.38 kernel packages by various developers.
As usual, you can click on each one to see how it affects your system, or go here for in-depth descriptions, as it affects other Linux operating systems as well.
Ubuntu 11.04 users can fix these security flaws if they upgrade to the linux-image-2.6.38-15 (2.6.38-15.59) package(s). To apply the update, run the Update Manager application or take a look at some detailed instructions: https://wiki.ubuntu.com/Security/Upgrades.
Don't forget to reboot your computer after the upgrade!
ATTENTION: Due to an unavoidable ABI change, the kernel packages have a new version number, which will force you to reinstall and recompile all third-party kernel modules you might have installed. Moreover, if you use the linux-restricted-modules package, you have to update it as well to get modules which work with the new Linux kernel version.