V3.11 — Mythos

Claude Mythos is a next-generation large language model developed by Anthropic . Unlike previous iterations like Opus or Sonnet, Mythos was designed with a specific focus on extreme capabilities in software engineering and cybersecurity.

: Internal frameworks like useMoreRight allow developers to compare Mythos's speculative predictions against real-world execution, creating a rapid training loop that continuously improves accuracy. The Security Scare Claude Mythos Preview System Card - Anthropic Mythos v3.11

The v3.11 designation is part of a series of internal and partner-only updates aimed at refining the model's precision. Key highlights of the Mythos family include: Claude Mythos is a next-generation large language model

: In evaluations, it has spotted undiscovered security holes that have existed for decades, outperforming both human experts and traditional automated tools. The Security Scare Claude Mythos Preview System Card

The Shadow of the Frontier: Understanding Mythos v3.11 As of late April 2026, a name is circulating through private forums and security briefings that has the entire AI industry on edge: . Specifically, the emergence of Mythos v3.11 (part of the larger Claude Mythos Preview family) represents a paradigm shift in how we view artificial intelligence—not just as a helpful assistant, but as a potent, frontier-level force. What is Mythos?

: Early reports suggest Mythos may be a 10 trillion parameter model designed to redefine industry benchmarks.

Anthropic recently made the unprecedented decision to , citing its advanced offensive cyber capabilities—such as autonomously finding and exploiting vulnerabilities in major operating systems and web browsers. Instead, it was restricted to select partners under Project Glasswing , an initiative designed to help organizations like Nvidia, Amazon, and JP Morgan Chase secure their infrastructure. Why "v3.11" Matters