A patch for Call of Duty: Ghosts appears to have altered the minimum spec requirements, lowering the RAM requirement to 4GB instead of the prior 6GB. This follows only weeks after fans called the 6GB requirement into question.
Though patch notes are unavailable, users on Reddit (via Polygon) noted a few of the changes from the patch. In addition to lowering the RAM requirement, it also purportedly fixes some menu stuttering and introduces eSports rules with Broadcaster mode.
The RAM change is likely to get the most attention, though. Though not necessarily related to the change, some Call of Duty fans had raised questions about the 6GB RAM requirement. One such example, in the video below, shows the game running just fine with only 4GB of RAM after circumventing the requirement. It seems like the game ran more-or-less fine (at least in single-player) with 4GB of RAM, and now it lets you do just that without resorting to system chicanery.