OpenAI confirms Astra is its first “Critical” cybersecurity model
OpenAI says Astra is the first model it has designated at the Critical cyber threshold: with tools, it can find previously unknown flaws and develop exploits across hardened systems without step-by-step human guidance. In evaluations, Astra scored 100% on ExploitBench, discovered two zero-days used in an exploit chain, and built working browser-escape and privilege-escalation chains; OpenAI plans a release soon, while initially restricting its strongest cyber capabilities to vetted defenders.
Why it made the cut: This is the first public confirmation that a frontier model has crossed OpenAI's highest tracked cyber-capability threshold, with real zero-day discovery—not just benchmark gains—and it changes the safeguards required for development and deployment.
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Official announcement · ↗Preparedness Framework · ↗
Independent analysis (WIRED)
Anthropic releases Fable 5.1 and restricted Mythos 5.1, with unusually strong agentic and scientific results
Anthropic released one underlying frontier model in two safety configurations: generally available Fable 5.1 and restricted Mythos 5.1 for vetted cybersecurity and life-science work. Anthropic reports Fable 5.1 more than doubled its predecessor's Terminal-Bench-Science score (52.6% versus 24.7%); in wet-lab validation, Mythos-designed protein binders reached nearly a 50% hit rate across 12 targets, with binders for three targets showing roughly 10× higher affinity than prior competition bests.
Why it made the cut: The release combines a large step in long-horizon research performance with externally tested physical-science outputs, including confirmed protein binding, rather than relying only on conventional language-model benchmarks.
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Official announcement · ↗
System card (PDF) · ↗
Released Venus elevation data · ↗
Independent coverage (Axios)