In the Opus 4.7 release notes they mentioned intentionally making it worse at cybersecurity. [0]

This suggests that they're doing the same thing with Mythos now and the Mythos we get will be nerfed in that department?

Or more precisely, I think they'll have two versions of Mythos, and the scary one will probably continue to require a lot of paperwork.

https://www.anthropic.com/news/claude-opus-4-7