Isn't OpenAI's public flagship already beating Mythos on penetration testing? I get the impression Mythos is just valuation-juicing for IPO more than anything else.

The fact that they haven't released it yet suggests a cost/margins issue to me more than anything else. Short term, I'll probably keep using Antrhopic, but my long-term bet is that locally-served models win, if only because the quest for profitability will probably lead to intentionally-nerfed / enshittified frontier models.

At other vendors, ad placement within LLM responses is either coming or already here. Anthropic's handling of OpenClaw shows they're willing to engage in anti-competitive behavior, and the courts are not in a hurry to stop them. Why would I pay them $200 a month for such treatment when a $2K box does what I need locally?

▲ ameliaquining 2 hours ago | parent | next [-]

Mythos is dramatically better specifically at finding zero-day vulnerabilities and developing exploits for them, that being what it was designed to do. On other cybersecurity tasks, GPT-5.5 is at least as good, but finding and exploiting zero-days is a particularly scary capability, which is why Mythos is a big deal. See, e.g., https://forum.effectivealtruism.org/posts/8yztpbjuPkyXsmA6n/....

	▲	stratos123 2 hours ago \| parent \| next [-]
		AFAIK, Antropic claims that they weren't aiming for zero-days specifically. From https://red.anthropic.com/2026/mythos-preview/ : `We did not explicitly train Mythos Preview to have these capabilities. Rather, they emerged as a downstream consequence of general improvements in code, reasoning, and autonomy. The same improvements that make the model substantially more effective at patching vulnerabilities also make it substantially more effective at exploiting them.` I've been assuming that Mythos is just a big jump in model size, and that's where the jump in capabilities comes from. Hence I expect OpenAI not to be able to catch up without scaling up the model and hence significantly raising the API prices.
	▲	alexgoodhart 2 hours ago \| parent \| prev [-]
		Anthropic frames this as something emergent. Not 100% but in a way they always phrase it as like, it’s a great model, but our breaths were swept and taken with its approach to security.

▲ srmatto 3 hours ago | parent | prev | next [-]

What benchmarks are you referencing that show a comparison of the models for penetration testing?

▲ senordevnyc an hour ago | parent | prev [-]

Please link to the $2k box that gives Opus level performance!