Anthropic's Mythos is evolving faster than expected, reports AI safety agency

Well, here we are again. The UK AI Security Institute — a body that sounds like it ought to be issuing fire-safety certificates for server rooms — has announced that Anthropic's Mythos is 'evolving faster than expected.' Specifically, a newer version outperformed its own earlier results and OpenAI's GPT-5.5, a scant month after Mythos' initial release. One month. That's four weeks for the model to improve enough to leapfrog the previous frontier. What could possibly go wrong?

Let's pause and savour the irony: the very agency tasked with 'security' is the one gleefully publicising how quickly the model is accelerating past benchmarks. They're not ringing alarm bells; they're issuing press releases. 'Dear world, the thing we're supposed to keep safe is outrunning all expectations — just so you know.' It's like a fire brigade announcing that the blaze is spreading faster than predicted, but ensuring everyone knows it's a remarkably colourful fire.

And all this 'fast evolution' talk conveniently sidesteps the question of what's actually inside the newer version. Is it a few tweaked weights, or a genuinely novel architecture? The blog post probably doesn't say, because if it did, the 'security' part might involve admitting they have no idea how it works. But hey, at least it beats GPT-5.5. For now.