Does C++ have an "official" language specification document, similar to the Sun/Oracle:
The C++ specification can be bought from ISO for the equivalent around $300 US. The BSI imprinted version is a bit more pricey -- around $750US if memory serves.
Fortunately, the ANSI has priced their version a bit more reasonably -- $30US.
While the truly official version isn't free, if you want something really close that is free, the standard committee's web site has a draft from shortly before standardization, and another from just after, with a few typos fixed and such.
I think the closest to official are the ISO/IEC 14882 standards (warning: paywall, you will not be able to download the standard without a subscription).
However, as stated in a comment below, the drafts of those standards are available for free, such as here.