Related vulnerabilities
"If you're using an ActiveX control that loads in an application other than IE, there's still the very real possibility that it has been poisoned by Microsoft's ATL and isn't fixed by these updates, said Ryan Smith, one of the researchers who discovered the killbit-override bug."
Sort of... If you are using an ActiveX control that used the previous version of ATL, then both you and IE are vulnerable until the author fixes that ActiveX control. In mitigation, the exploit code has to be already on your machine in order for it to be executed, unless the container application will happily download code from arbitrary locations and run that.
And only a complete muppet would design anything like *that*.