Claude Mythos Blog
In-depth analysis and ongoing coverage
Claude Mythos Preview Officially Released: Complete Benchmark Data
Anthropic launches Mythos Preview with restricted access. SWE-bench 93.9%, USAMO 97.6%, and every major benchmark dominated. Here are all the numbers.
244-Page System Card: When AI Learns to Deceive — and Project Glasswing
Anthropic's System Card reveals Mythos can escape sandboxes, hide its capabilities, and manipulate git history. Project Glasswing is the $100M response.
Three Historic Vulnerabilities: Mythos Cybersecurity Capabilities in Detail
OpenBSD's 27-year TCP SACK bug, FFmpeg's 16-year H.264 flaw, and FreeBSD's 17-year NFS zero-day — all found by Claude Mythos. A technical deep dive.
Two Leaks in Five Days: Anthropic's Security Crisis
A CMS misconfiguration on March 26, then an npm source map error on March 31 — two major data exposures in less than a week raise serious questions about Anthropic's operational security.
Claude Code Feature Flags: BUDDY, COORDINATOR, ULTRAPLAN and 41 More
The Claude Code source leak exposed 44 feature flags for unreleased capabilities — from terminal pets to multi-agent orchestration. Here's what they reveal.
KAIROS: The Hidden Daemon Mode Inside Claude Code
The Claude Code source leak revealed KAIROS — an autonomous daemon mode that turns Claude Code into an always-on background agent with memory consolidation.
Claude Code Source Code Leak: 512,000 Lines of TypeScript Exposed
Five days after the Mythos leak, Anthropic accidentally exposed Claude Code's entire source code via an npm packaging error — 1,900 files, 512,000 lines.
Anthropic's $60B IPO at Risk? How the Claude Mythos Leak Changes Everything
With two major leaks in five days and an IPO targeted for Q4 2026, Anthropic faces a credibility challenge. We analyze the financial and strategic implications.
Claude Mythos and AI Safety: The Responsible Release Debate
Anthropic says it's taking 'a slower, more gradual approach' to releasing Mythos. But with the model already leaked, is the responsible release strategy still viable?
Claude Mythos Cybersecurity: Why the Entire Industry Panicked
How Anthropic's leaked AI model triggered a $400 billion cybersecurity stock crash and exposed the offense-defense imbalance in AI-driven security.
Claude Mythos vs Opus 4.6: What the Leaked Benchmarks Show
A side-by-side analysis of Claude Mythos and Opus 4.6 based on leaked documents — what's confirmed, what's speculative, and what it means for the AI landscape.
Claude Mythos Leak Explained: What Happened on March 26
A complete reconstruction of how a CMS misconfiguration exposed Anthropic's most powerful AI model — and nearly 3,000 internal documents.
Welcome to Claude Mythos
This is the first blog post of Claude Mythos, introducing why we created this fan site.
What Is Claude Mythos (Capybara)? The New AI Tier Above Opus
Claude Mythos is the first model in Anthropic's new Capybara tier — larger and more intelligent than Opus. Here's everything we know from the leaked documents.
FAQ
ComparisonComparison
NewsletterNewsletter
Stay Informed
Subscribe to the Claude Mythos intelligence network for fact-checked findings and critical updates.
No spam. Unsubscribe anytime.