Anthropic is investigating a possible breach of Mythos, a new model the artificial intelligence company  rolled out  to a small pool of companies earlier this month to help them detect software vulnerabilities.  The AI company behind the chatbot Claude is looking into a report of unauthorized access to Mythos from one of its third-party vendor environments, an Anthropic spokesperson told CBS News in an email.  Anthropic works with a small number of third-party vendors to develop its AI models.