(AP)- - SEATTLE Microsoft has released six patches to fix critical flaws in its software.
The company says all six flaws could allow an attacker to obtain some access to other people's computers.

The software maker also released four other patches to fix vulnerabilities that the company says are less severe.

Customers can download all the patches for free on Microsoft's security Web site.

Microsoft said last month that it knew attackers were already trying to take advantage of defects in its Windows operating system, Microsoft Word software and PowerPoint presentation program.

Such vulnerabilities are rare. In most cases, security experts quietly provide Microsoft evidence of a security flaw, allowing the company to fix the problem in secret and release a patch before attackers can take advantage of it.

But recently, the company has been hit with a number of so-called "zero-day" attacks, in which flaws are targeted before Microsoft is aware of them or can release patches.