Boeing's new 787 Dreamliner passenger jet may have a serious security vulnerability in its onboard computer networks that could allow passengers to access the plane's control systems, according to the U.S. Federal Aviation Administration.

The computer network in the Dreamliner's passenger compartment, designed to give passengers in-flight internet access, is connected to the plane's control, navigation and communication systems, an FAA report reveals.

The revelation is causing concern in security circles because the physical connection of the networks makes the plane's control systems vulnerable to hackers. A more secure design would physically separate the two computer networks. Boeing said it's aware of the issue and has designed a solution it will test shortly.

Currently in the final stages of production, the 787 Dreamliner is Boeing's new mid-sized jet, which will seat between 210 and 330 passengers, depending on configuration.

Boeing says it has taken more than 800 advance orders for the new plane, which is due to enter service in November 2008. But the FAA is requiring Boeing to demonstrate that it has addressed the computer-network issue before the planes begin service.