Question 1

What is Claude Mythos Preview?

Accepted Answer

Claude Mythos Preview is Anthropic's most powerful AI model, announced on April 7, 2026. It is a general-purpose frontier model that excels at coding, reasoning, and cybersecurity tasks, outperforming publicly available models on major benchmarks including SWE-bench Verified (93.9%) and CyberGym (83.1%).

Question 2

Can I use Claude Mythos through the API or Claude.ai?

Accepted Answer

No. Anthropic has not made Claude Mythos Preview generally available. It does not appear in Claude.ai's model selector or the public API. Access is currently limited to founding partners in Project Glasswing and about 40 additional organizations that maintain critical software infrastructure.

Question 3

What is Project Glasswing?

Accepted Answer

Project Glasswing is Anthropic's cybersecurity initiative that gives select partners, including AWS, Microsoft, Apple, Google, and CrowdStrike, access to Claude Mythos for defensive security work. Anthropic has committed up to $100 million in usage credits and $4 million in donations to open-source security organizations.

Question 4

How does Claude Mythos compare to GPT-5.4?

Accepted Answer

Claude Mythos leads GPT-5.4 by significant margins: 77.8% vs. 57.7% on SWE-bench Pro, 82.0% vs. 75.1% on Terminal-Bench 2.0, and 97.6% vs. 95.2% on USAMO 2026. The gap is widest on cybersecurity benchmarks, where Mythos scores 83.1% on CyberGym and 100% on Cybench CTF.

Question 5

Will Claude Mythos ever be publicly released?

Accepted Answer

Anthropic has said it wants to learn how Mythos-class models could eventually be deployed at scale, but there is no public timeline. The company plans to develop and test new safeguards with an upcoming Claude Opus release before considering broader access for Mythos-class models.

Question 6

What vulnerabilities has Claude Mythos actually found?

Accepted Answer

Anthropic reports thousands of zero-day vulnerabilities across every major operating system and web browser. Disclosed examples include a 27-year-old OpenBSD remote crash vulnerability, a 16-year-old FFmpeg bug missed by five million automated tests, Linux kernel privilege escalation chains, and a Firefox browser exploit that chained four vulnerabilities to escape both renderer and OS sandboxes.

Claude Mythos: The AI Model Anthropic Built (and Refused to Release)

Claude Mythos: The AI Model Anthropic Built (and Refused to Release)

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