(Reuters) - Johnson &amp; Johnson is telling patients that it has learned of a security vulnerability in one of its insulin pumps that a hacker could exploit to overdose diabetic patients with insulin, though it describes the risk as low.<div><a href="http://feeds.reuters.com/~ff/reuters/technologyNews?a=Roi1BSg3EUA:p-MRz60CgkM:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/reuters/technologyNews?d=yIl2AUoC8zA" border="0" /></a> <a href="http://feeds.reuters.com/~ff/reuters/technologyNews?a=Roi1BSg3EUA:p-MRz60CgkM:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/reuters/technologyNews?i=Roi1BSg3EUA:p-MRz60CgkM:V_sGLiPBpWU" border="0" /></a> <a href="http://feeds.reuters.com/~ff/reuters/technologyNews?a=Roi1BSg3EUA:p-MRz60CgkM:-BTjWOF_DHI"><img src="http://feeds.feedburner.com/~ff/reuters/technologyNews?i=Roi1BSg3EUA:p-MRz60CgkM:-BTjWOF_DHI" border="0" /></a></div><img src="http://feeds.feedburner.com/~r/reuters/technologyNews/~4/Roi1BSg3EUA" height="1" width="1" alt="" />