"There are reports that the vulnerability is being exploited in the wild in active targeted attacks designed to trick the user into clicking on a malicious file delivered in an email message," the Friday said.

Although all editions of Flash Player contain the vulnerability and should be patched, the active exploit is targeting only users of Microsoft's Internet Explorer (IE).

Flash Player for IE is an ActiveX plug-in, the Microsoft-only standard; other browsers, including Firefox and Chrome, use a different plug-in structure.

The update was pegged with Adobe's priority rating of "1," used to label patches for actively-exploited vulnerabilities or bugs that will likely be exploited. For such updates, Adobe recommends that customers install the new version within 72 hours.

Adobe disclosed relatively few details about the vulnerability -- its usual practice -- other than to label it an "object confusion vulnerability," note the Common Vulnerabilities & Exposures ID of CVE-2012-0779, and acknowledge that triggering the bug "could cause the application to crash and potentially allow an attacker to take control of the affected system."