In initial disclosures about critical security flaws discovered in its processors, Intel Corp. notified a small group of customers, including Chinese technology companies, but left out the U.S. government, according to people familiar with the matter and some of the companies involved.

The decision raises concerns, security researchers said, as it potentially could have allowed information about the chip flaws, dubbed Spectre and Meltdown, to fall into the hands of the Chinese government before being publicly divulged. There...