A new version of Flash was announced by Adobe today. Version 11.8.800.168 fixes four critical vulnerabilities. The official release announcement from Adobe provides details on all of the changes in this new version.

Anyone who uses a Flash-enabled web browser should install the new version as soon as possible. That includes anyone who uses Youtube.

The changes in this version will be ported to the Chrome web browser as embedded Flash version 11.8.800.170. Flash updates for Chrome tend to happen silently in the background. You can see what version of Flash Chrome is currently running by browsing to the chrome://flash/ page. Recently, the version of Flash in Chrome mysteriously rolled back to 11.8.800.97, so it will be interesting to see what happens with 11.8.800.170 (Chrome finally updated itself with Flash 11.8.800.170 on 2013Sep18, a delay of one week, which is somewhat alarming. The version of Chrome itself also changed at the same time, to 29.0.1547.76.)

Internet Explorer 10 on Windows 8 also uses embedded Flash code. Microsoft Security Advisory 2755801, now available from Windows Update, patches IE10 on Windows 8 to use the new Flash version 11.8.800.168.