Bonn, Germany - People whose computers use the Firefox browser should plan on an upgrade.

Eleven different bugs have been found in the free browser created by Mozilla, according to the German Federal Office for Security in Information Technology in Bonn.

Similar problems have been discovered in Seamonkey and Thunderbird, two other applications from the same company.

Five of the flaws have been characterized as critical. A new bug- free version of Seamonkey, a browser and e-mail program, has already been released.

However, a new version of the mail client Thunderbird is not yet available (dpa)