Eugene Mymrin/ Moment via Getty Images Follow ZDNET:  Add us as a preferred source  on Google. ZDNET's key takeaways The latest version of Claude Mythos has already advanced. External researchers found that it achieved several firsts in testing.  AI capabilities may be improving much faster than anticipated.  Anthropic's Claude Mythos , which the company maintains is too powerful to be released generally, already appears to have gained new capabilities.  In a blog  post on Wednesday, the UK AI Security Institute (AISI) reported that it had tested a newer version of Mythos, which outperformed both its earlier results and OpenAI's GPT-5.5 -- just a month after Mythos' initial release.  Also:  Apple, Google, and Microsoft join Anthropic's Project Glasswing to defend world's most critical software "The newer Mythos Preview checkpoint completed both our cyber ranges, solving the range 'The Last Ones' in 6 of 10 attempts and the previously unsolved 'Cooling Tower' in 3 of 10…