"We saw the tweet, but further details have not been shared with us," Forstrom said in a statement.

Vupen's Twitter message, written on Wednesday, implies the vulnerability would allow a hacker to bypass security technologies contained within Windows 8, including high-entropy Address Space Layout Randomization (ASLR), anti-Return Oriented Programming and DEP (data execution prevention) measures. The company also indicates it is not dependent on a problem with Adobe System's Flash multimedia program.

"Certainly, if the bug is confirmed, then this could be a black eye for Microsoft having their brand new and touted most secure platform already found flawed just after its public release," said Andrew Storms, director of security operations for nCircle.

The market opportunity for a successful exploit may be limited due to the recent release of Windows 8, but "on the other hand, nobody has confirmed this bug isn't also functional on older version of Windows or IE," Storms said.

Jody Melbourne, a penetration tester and senior consultant with the Sydney-based Australian security company HackLabs, said the vulnerability could be useful to third-party Microsoft developers interested in stealing code-signing certificates or source code.