Google released a number of security updates for the Google Chrome Stable Channel. These updates affect OS X and Linux (updated to Chrome 21.0.1180.57), as well as Windows and Chrome Frame (Chrome 21.0.1180.60).

Chrome 21 includes patches that address 15 security vulnerabilities. One vulnerability was rated critical; of the others, six were rated high, five medium, and three low. Five of the weaknesses affected Chromes built-in PDF viewer and could have caused memory corruption, a program crash, or other unexpected behavior. Google also patched a vulnerability that could give an attacker unusually broad file access via Chromes implementation of drag and drop, among other vulnerabilities, as well as several nonsecurity-related bugs.

and for more on the Chrome 21 fixes.