Other answers state that there is no official style guide, which was true at the time.
But in 2015, Bjarne Stroustrup announced the C++ Core Guidelines, an open source project to build authoritative guidelines for modern C++ code, led by Stroustrup himself and published by the Standard C++ Foundation:
http://github.com/isocpp/CppCoreGuidelines
In relevance to this question, the Core Guidelines also link to other guidelines, with added comments. About the often recommended Google C++ Style Guide, they say:
Geared toward C++03 and (also) older code bases. Google experts are now actively collaborating here on helping to improve these Guidelines, and hopefully to merge efforts so these can be a modern common set they could also recommend.