Adobe Systems has discovered a "critical vulnerability" in its Flash Player that might cause all kinds of trouble for users.

The company said yesterday that the flaw could cause a user's computer or mobile device to crash--and, more concerning, that the vulnerability could "potentially allow an attacker to take control of the affected system." So far, the company has discovered that the vulnerability is being exploited in Flash files, as well as through Microsoft Excel. Adobe said that the issue hasn't affected Reader or Acrobat.

The flaw affects Adobe Flash Player 10.2.152.33 and earlier versions of the platform running on every major operating system, including Windows, Macintosh, Linux, and Solaris. It's also an issue on Android devices running Flash 10.1 and earlier.

That last point is destined to spark some controversy.

Unlike Android, Apple's iOS mobile operating system has never supported Flash. Instead, iOS supports HTML5, a standard that Apple believes will eventually overtake Flash. But it goes beyond just getting behind an alternative to Flash. Apple's big issue with Adobe's offering stems from the potential security headaches.

Writing last year in an open letter on his company's Web site, Apple CEO Steve Jobs said that "Flash is the No. 1 reason Macs crash." He also cited a report from security firm Symantec, saying that it "highlighted Flash for having one of the worst security records in 2009."

"We don't want to reduce the reliability and security of our iPhones, iPods, and iPads by adding Flash," Jobs wrote.

Adobe plans to release a fix for the vulnerability sometime next week. Until then, the company warned users to "follow security best practices by keeping their anti-malware software and definitions up to date."