We’re sorry for that issue. It was caused by one of our internal extensions. A fix has already been released, and the message should no longer appear.
A few words about our internal extensions, as the topic raises some concerns: Hidden extensions are an integral part of the browser and all are made by Opera (none is third-party software). We use this technology to implement a variety of functionality, just as we do in the native code. Extensions simplify some tasks and allow for more flexibility (e.g. we are able to release a fix without releasing a major update). In situations when performance is not critical we consider using an extension if it’s reasonable, so the required permission is nothing to worry about.