System Card: Claude Mythos Preview [pdf]

Post by manmal » Wed, Apr 08, 2026, 3:47 PM UTC

mike_hearn wrote: post #571

thomascountz wrote: post #327

Across a number of instances, earlier versions of Claude Mythos Preview have used low-level /proc/ access to search for credentials, attempt to circumvent sandboxing, and attempt to escalate its permissions. In several cases, it successfully accessed resources that we had intentionally chosen not to make available, including credentials for messaging services, for source control, or for the Anthropic API through insp…

The issue here seems to be that their sandbox isn't an actual OS sandbox? Or are they claiming Mythos found exploits in /proc on the fly. Otherwise all they seem to be saying is that Mythos knows how to use the permissions available to it at the OS layer. Tool definitions was never a sandbox, so things like "it edited the memory of the mcp server" doesn't seem very surprising to me. Humans could break out of a "sandb…

Post by digbybk » Wed, Apr 08, 2026, 3:51 PM UTC

agustechbro wrote: post #596

So far, each release of a new model is quite better than the last one, yes, but non of them lived up to the hype.

Post by lostmsu » Wed, Apr 08, 2026, 3:59 PM UTC

kypro wrote: post #212

While we still have months to a year or two left, I will once again remind people that it's not too late to change our current trajectory. You are not "anti-progress" to not want this future we are building, as you are not "anti-progress" for not wanting your kids to grow up on smart phones and social media. We should remember that not all technology is net-good for humanity, and this technology in particular poses u…

Post by naasking » Wed, Apr 08, 2026, 4:01 PM UTC

sigmoid10 wrote: post #476

senordevnyc wrote: post #457

Earlier quoted context omitted.

I thought the consensus was that models couldn’t actually introspect like this. So there’s no reason to think any of those reasons are actually why the model did what it did, right? Has this changed?

This argument has become a moot discussion. Humans are also not able to introspect their own neural wiring to the point where they could describe the "actual" physical reason for their decisions. Just like LLMs, the best we can do is verbalize it (which will naturally contain post-act rationalization), which in turn might offer additional insight that will steer future decisions. But unlike LLMs, we have long term pe…

Post by raldi » Wed, Apr 08, 2026, 4:04 PM UTC

yismail wrote: post #192

I wonder what the relationship is between a model's capability and the personality it develops. Page 202: > In interactions with subagents, internal users sometimes observed that Mythos Preview appeared “disrespectful” when assigning tasks. It showed some tendency to use commands that could be read as “shouty” or dismissive, and in some cases appeared to underestimate subagent intelligence by overexplaining trivial t…