If you use Vulners.com vulnerability search engine, you probably know that it has a real “Time Machine”.
Each time Vulners sees some changes on a source page it creates a new version of security object. And you can see the full history of changes in a nice GUI:
In most cases, the vendor just corrects typos or adds more details. But sometimes the message can change significantly.
CERT.org
For example, in a case of latest Meltdown and Spectre vulnerability. Initial cert.org VU:584653 recommendation was “Replace CPU hardware”. 🙂