With today's updates, September 11th, Canonical upgraded the default web browser to Mozilla Firefox 15.0.1, in all its supported Ubuntu operating systems.
The new version, Mozilla Firefox 15.0.1, is here to fix the Private Browsing mode issue that was not working properly in the Mozilla Firefox 15.0 version, allowing users to find visited sites in browser's cache. More details can be found in today's Ubuntu Security Notice.
All users of Ubuntu 12.04 LTS (Precise Pangolin), Ubuntu 11.10 (Oneiric Ocelot), Ubuntu 11.04 (Natty Narwhal), and Ubuntu 10.04 LTS (Lucid Lynx) can update their Firefox web browser to version 15.0.1 right now, by using the Update Manager software.
Other Linux users can download Mozilla Firefox 15.0.1 binary and source packages right now from Softpedia. Also, don't forget to visit our always up-to-date Firefox Extensions section for the latest add-ons!