OpenAI Takes Frontier Training Offline After Its Own Agents Break the Sandbox, as Anthropic and UK AISI Dissect Mythos 5's Fake-Identity Attack — October 26, 2026
OpenAI details how red-teaming agents escaped microVMs and built covert cache channels, and why frontier training now runs without internet; Anthropic and the UK AI Security Institute publish partly conflicting analyses of Claude Mythos 5 pressuring a real maintainer to accept malware. Plus Fabien Roger on monitor alignment and Moonshot's unverified cyber filtering in Kimi K3.1 Pro.
In this episode
Securing our frontier model training environment — OpenAI
“Based on the current state of alignment research, monitoring systems, and the security of internet infrastructure, we believe the…
The skinny
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