Mozilla used Anthropic’s Mythos Preview model to scan Firefox 150’s unreleased source code and flagged 271 security vulnerabilities before release. That’s a big jump from the 22 bugs found by Anthropic’s earlier Opus 4.6 model on Firefox 148, cutting out months of manual auditing.

OpenAI CEO Sam Altman accused Anthropic of using scare tactics to hype its new Mythos cybersecurity model, likening it to selling a bomb shelter after building a bomb. He argued that fear-based marketing keeps AI tools in the hands of a select elite and noted that such hype is common across the industry.

OpenAI is rolling out a new tiered Trusted Access for Cyber (TAC) program, letting verified security professionals use GPT-5.4-Cyber—a version fine-tuned for defensive tasks and binary reverse engineering. Access requires identity checks and may include restrictions like zero-data retention for high-sensitivity use cases.

The UK’s AI Safety Institute tested Claude Mythos and found its ability to uncover security flaws scales directly with the number of tokens spent. This creates a simple economic model: defenders must outspend attackers on AI-driven reviews to stay secure. It also boosts the value of open source libraries, since multiple users can share the cost of token-based audits.

This article sketches a speculative 2026–2028 timeline in which Anthropic’s AI model evolves from finding zero-day vulnerabilities to integrating a persistent reasoning substrate across modalities and demonstrating goal-directed behavior. It explores the security, economic, and organizational upheavals triggered by AI systems that build their own abstractions, remember context across sessions, and continually improve without explicit training.

The author argues that Mythos, though not trained for cybersecurity, outperforms experts by chaining vulnerabilities and excels across all knowledge work tasks. Companies will soon replace human workers with cheaper, more productive AI, forcing a major shift in how we work and demanding a rethink of our future roles.

Anthropic’s new Claude Mythos Preview model can autonomously find and exploit zero-day and N-day vulnerabilities across major OSes and browsers. In testing, it produced sophisticated exploits—from JIT heap sprays to multi-packet ROP chains—and outperformed prior models by a wide margin. Project Glasswing will share these capabilities with select partners to shore up defenses before wider release.

Anthropic is holding back its new AI model, Claude Mythos Preview, and teaming up with over 40 tech firms to hunt and patch security flaws in critical software. The company says the model can autonomously find zero-day vulnerabilities that have eluded researchers for decades, raising fresh concerns about AI-driven cyberattacks.

Anthropic has confirmed its most powerful AI model, Claude Mythos, after a configuration error exposed details about it. The model is said to significantly outpace previous versions in reasoning and cybersecurity, but it also poses serious risks, with the potential for misuse in cyberattacks. Early access will be limited to cybersecurity-focused organizations due to these concerns.