The company categorized the vulnerability to its Flash Communication Server MX as "important," and said on its website that it could crash PCs in some cases.
"Macromedia categorizes this issue as an important issue and recommends users patch their installations," the company said. "The vulnerability that causes server instability is known to be triggered by a single alpha release build of Flash Player 8.5. The update patch fixes this issue by preventing the server from entering an unstable state."
Flash Communication Server MX 1.0 and 1.5 were listed by Macromedia as affected servers.
The company released another advisory on Nov. 2, months after the flaws were reported by eEye Digital Security and Sec Consult in June.
Macromedia had recommend that users fix that vulnerability, present in Flash Player 7 and earlier models, by downloading Flash Player 8.
Marc Maiffert, chief hacking officer for eEye Security, said Thursday that he wouldn't be surprised if other vulnerabilities appeared in Macromedia products in coming weeks.
"Microsoft has done better than a lot of other, smaller companies to try to prevent this," he said. "A lot of the other software vendors haven't done as much internally."www.macromedia.com