Claude Mythos Executes End-to-End Intrusion From Initial Access to Full Domain Compromise
Anthropic's Claude Mythos Preview, its most cyber-capable model, autonomously completed an end-to-end enterprise intrusion simulation in restricted-access testing.
Anthropic's April 2026 system card describes Claude Mythos Preview as the first model to solve a private cyber range end to end and finish a corporate-network attack simulation an expert would need 10+ hours to complete. It scored 100% pass@1 on a 35-challenge Cybench subset and 0.83 on CyberGym versus 0.67 for Claude Opus 4.6. The model is limited to vetted partners under Project Glasswing; it failed an OT cyber range and could not find novel exploits in a fully patched sandbox.
- Model chained recon, exploitation, and lateral movement across a weakly defended enterprise range
- Exploited four distinct bugs in Firefox 147 evaluation versus one for Opus 4.6
- Restricted release via Project Glasswing for defensive-use cybersecurity partners
- Anthropic cautions result reflects weak defenses, not hardened-enterprise compromise capability
- Organizations
- Anthropic
From the original article
3 min read at gbhackers.com
Anthropic’s Claude Mythos Preview has demonstrated the ability to complete an end-to-end enterprise intrusion simulation, progressing from initial access through chained exploitation and network traversal to the defined compromise objective.
By Mayura Kathir · gbhackers.com
A short excerpt; the article and its images belong to the publisher. Summary, key facts and assessment above are AI-written from the article and can be wrong.