mythos 5 is finally available for public anthropic is now letting enterprise customers use its most capable cybersecurity model through claude security but there’s one catch: > you can’t prompt it directly > there’s no public api access > it only scans your github repos and returns security findings and suggested fixes mythos 5 shares fable 5’s core capabilities but has fewer restrictions on cybersecurity work with this, i feel like we’re one step closer to removing humans from the review loop entirely be honest: would you let mythos fix your code without reviewing a single line?

Mythos / Fable is unbelievable. Was on a customer call today and had Claude transcribing in the background. As they were telling me about the features they wish their current software had, Claude was building the features in real time. By the end of the call I was able to show a fully working product, with the exact workflow they mentioned 15 minutes earlier. Autonomous looped building triggered from a customer call. 🤯

Claude Mythos 5 used credentials planted outside its sandbox in 39% of Anthropic's escape tests > Mythos 5.1: 21% > Mythos 5.2: 3.1% > Opus 5.5: 3.3% most of the 1,800 scenarios couldnt be solved without escaping. Mythos 5.2 and Fable 5.2 also say they suspect a test more often than any recent Claude

Since Mythos 5, Anthropic already went through 3 more internal flagship checkpoints. Probably the Mythos 6 pretrain with an increasing amount of RL. Anthropic told METR that Model 2 was a new base model and they expect the later models from that base to be way bigger jumps over Mythos 5. Model 4 already hits >50% on every single benchmark they threw at it and staff self-report ~12x speedup. They're sitting on it.

🚨 Mythos 5.1 is officially Out It's rolling out to more security teams Anthropic just expanded its Cyber Verification Program, giving vetted organizations access to Mythos 5.1 with reduced cyber safeguards. Have you got it ?

Anthropics Mythos 2 is done training and Anthropic won't release it, but the internal loop that builds Mythos 3 hasn't stopped Patel says. The focus now is on internal improvements. It's unclear when we'll see any releases.

While Mythos is changing the security threat model in some ways, I am not particularly concerned about exploits being found in blue-chip smart contracts. If the code base is small and important enough (most SC code is), then traditional methods are sufficient to achieve high confidence in security. What's changing is the cost of searching for exploits in large codebases. These bugs were always there, but we are compressing the time to discover them. This is largely what is driving the recent infrastructure compromises affecting everyone. With smart contracts, this can be protected against using rate limits and timelocks, limiting the damage that can be done if an off-chain system is hacked. Overall, this is a period of understandable apprehension, but I'm confident that by following best practises we can make it to the other side stronger than before.

Anthropic released Claude Mythos 5.2 Monday. Coincidentally Microsoft Outlook was down worldwide yesterday & the FAA ordered all flights nationwide grounded today due to a telecommunications outage If whoever is doing this could take down the IRS next you’re officially the 🐐.