For the next occasion in nine months, Microsoft thought it would not patch susceptibility in an older product since create a fix was "infeasible."

The oversight leaves clients running Office XP weak to assault if not they take additional steps on their own.

Office XP, which debuted in March 2001, leftovers on Microsoft's list of supported group users will carry on to accept security updates during mid-July 2011. But, Microsoft said COM (component object model) corroboration weakness in the aged suite couldn't be patched.

The decision was clarify in one of the 10 updates Microsoft issued yesterday that patched a record-tying 34 vulnerabilities.

"The architecture to correctly support the fixes to correct validation does not exist on Microsoft Office XP, making it infeasible to build the fixes for Microsoft Office XP products to remove the exposure," said Microsoft in the MS10-036 security bulletin.

"To do so would need again architecting a very important amount of the Microsoft Office XP products, not just the affected components."