Infinity Ward has revealed that a new security patch is nearing completion for Call of Duty: Modern Warfare 2. It will address concerns primarily on the PlayStation 3, but there are also issues regarding the Xbox 360 and PC versions too that will be addressed.
The patch is currently going through internal quality assurance, but Robert Bowling, Infinity Ward's community manager, wouldn't give a confirmed date of release for the patch.
Alongside the security fixes will be a patch to fix a small geo exploit on the map "Fuel", which had a hole that players could exploit to get outside of the map.
Source: Infinity Ward Forums