Advanced Micro Devices Inc. surged in early trading after a report that Intel Corp., its only remaining rival in the market for personal computer processors, has a flaw in its products that makes commonly used operating systems vulnerable to hackers.

According to technology website The Register, Intel has a bug that lets some software gain access to parts of a computer’s memory that are set aside to protect things like passwords. Patches to Microsoft Corp.’s Windows and Apple Inc.’s OS X operating systems will be required and the security updates may slow down older machinery.

AMD shares surged as much as 6.2 percent to $11.66 Wednesday. Intel fell 2 percent to $45.90.

Intel’s microprocessors are the fundamental building block of the internet, corporate networks and PCs. The company has added to its designs over the years trying to make computers less vulnerable to attack, arguing that hardware security is typically tougher to crack than software.

The Santa Clara, California-based company’s chips have more than 80 percent market share overall and more than 90 percent in laptops and servers.