OpenAI unveiled GPT‑5.5‑Cyber as part of its Daybreak security initiative, delivering a full‑capability model that outperforms Anthropic’s Mythos 5 on multiple security benchmarks and can autonomously discover, verify, and patch software vulnerabilities while launching the open‑source “Patch the Planet” program.
In mid‑June 2024 Anthropic released Claude Fable 5, and within 24 hours a hacker posted the model's full 120,000‑character system prompt—covering personas, safety rules, downgrade policies, and more—on the public GitHub repository elder‑plinius/CL4R1T4S, revealing its close relationship with Claude Mythos 5.
The Trump administration has invoked national‑security powers to place Anthropic’s latest AI models, Claude Fable 5 and Mythos 5, under strict export controls, prohibiting any foreign government, company or individual from accessing them, citing concerns over potential jailbreaks and broader security risks.
The Trump administration’s export‑control ban on Anthropic’s Fable 5 and Mythos 5 models, allegedly prompted by an Amazon report on a jailbreak, sparked speculation about motives, impacts on staff like Andrej Karpathy, and potential winners such as OpenAI.
Anthropic halted all customer access to its Fable 5 and Mythos 5 models after a U.S. government export‑control order citing national‑security concerns over a potential jailbreak, sparking debate over regulatory standards and the broader impact on AI developers and enterprises.
The US Trump administration has invoked national‑security powers to place export controls on Anthropic’s latest AI models, Fable 5 and Mythos 5, completely prohibiting foreign governments, companies, and individuals from accessing them amid concerns over potential jailbreaks and broader AI safety risks.
Anthropic released two new Claude models—Fable 5, open to all users with a safety classifier, and Mythos 5, a restricted, high‑security version—both achieving record‑breaking performance on software‑engineering, research, vision, and long‑context tasks, while offering a pricing model of $10 per M input tokens and $50 per M output tokens.
The article benchmarks Anthropic's Claude Fable 5 and Mythos 5, revealing superior performance on long, complex coding and AI tasks, detailed real‑world reproductions of a Shopify site and a DDIM paper, high safety‑guardrail trigger rates, and a total testing cost of about $108.
Anthropic’s June 9 launch of Claude Fable 5 and Claude Mythos 5 introduces a Mythos‑class model split into a public‑ready “Fable” version and a trusted‑partner “Mythos” version, highlighting stronger coding, long‑task, vision, and research abilities, a safety‑first distribution framework, and the shifting focus from raw model power to controlled, low‑friction AI deployment.
Anthropic’s newly released Claude Fable 5, the first publicly available Mythos‑level model, delivers SOTA performance across software engineering, coding, visual tasks and scientific research—outperforming GPT‑5.5 and Gemini on benchmarks—while offering a modest $10/$50 token pricing and a 5 % safety fallback that trades some flexibility for stronger safeguards.
