Google has released a new version of its Web browser, Chrome 21·0·1180·75, for all platforms (Linux, Windows, Mac OS X, and Chrome Frame); it fixes a number of bugs, mostly related to stability and user interface issues. The new version also fixes two security vulnerabilities in Chrome, both of which Google rates as High severity. More details on the flaws patched are in the Release Announcement.
Because of the security content of the new version, I recommend that you update your systems as soon as you conveniently can. Windows and Mac users should get the new version via the built-in update mechanism. Linux users should get the updated package from their distributions’ repositories, using their standard package maintenance tools.
You can check the version of Chrome that you have by clicking on the tool menu icon (the little wrench), and then selecting “About Google Chrome”.