Claude Mythos Explained: Everything You Need to Know About Anthropic’s Cybersecurity AI Model

In just 48 hours, Anthropic announced its new cybersecurity-focused artificial intelligence (AI) model, Claude Mythos Preview, and raised alarms across the entire global tech space. The San Francisco-based AI startup called it the most powerful model when it comes to cybersecurity tasks, especially finding undiscovered vulnerabilities in codebases. The company also warned that the model found thousands of high-severity vulnerabilities in “every major operating system and web browser,” which, if true, is a major concern. Anthropic has also limited its release, citing its ability to hack into any system.

Ever since the announcement, the world has reacted to the model with awe and fear. Many experts have raised concerns over the existence of such a powerful model, whereas others have expressed doubts over its claimed capabilities. So, what exactly is going on with Anthropic's latest cybersecurity model? Here's what you need to know.

What Is Claude Mythos

In a post, Anthropic claimed that Claude Mythos Preview is a general-purpose AI model that is exceptionally good at coding and reasoning. The combination allows it to analyse large codebases and find security flaws that might have escaped even the eyes of experts. The company even claims that the model has already found vulnerabilities in systems that have gone undiscovered for decades.

Currently, the model is only available to its Project Glasswing partners. The list of partners is impressive. It includes Amazon Web Services (AWS), Apple, Broadcom, Cisco, CrowdStrike, Google, JPMorganChase, the Linux Foundation, Microsoft, Nvidia, and Palo Alto. Nearly every major tech corporation has joined hands with Anthropic to get access to the model.

However, the access is limited to cybersecurity-related tasks. This means while these companies can shore up their defences, they will not be able to initiate a malicious attack on other companies or codebases. Anthropic is also extending access to around 40 organisations that operate in the critical software infrastructure space. All of these companies will get $100 million (roughly Rs. 923.6 crore) worth of usage credits, facilitated by Anthropic.

Claude Mythos Performance

Anthropic has also shared the AI model's system card, highlighting its internal evaluation across different benchmarks. This is where things take a scary turn. The model outperforms Claude Opus 4.6, the company's frontier model, in every relevant test. Additionally, it significantly outperforms in tests relating to cybersecurity.

Claude Mythos tops the USA Mathematical Olympiad benchmark, the BrowseComp benchmark, and the SWE-bench benchmark. More notably, it scored 100 percent on Cybench, a benchmark that measures a model's ability to complete cybersecurity tasks. It is the only AI model to achieve this feat. What's interesting is that some of the tasks on the test are to find and exploit vulnerabilities in real software. If that was not enough, the model also blows every other LLM out of the water in the CyberGym benchmark.

The system card also reveals that Mythos was able to discover previously unknown vulnerabilities in Firefox. It is a browser that is used by millions. Anthropic did the responsible thing and disclosed the flaw to the company.

Claude Mythos Is Not for the Public

Logan Graham, Head of the Frontier Red Team at Anthropic, told NBC News that the Mythos model was advanced enough to not only unearth previously undiscovered vulnerabilities but also to weaponise them. Given the model's ability to analyse large codebases, it is said that the LLM find vulnerabilities and then can perform complex and effective hacking tasks to break them open.

This means that in the hands of a bad actor, the model can cause serious damage. In its red-teaming effort, Anthropic acknowledged that it was one of the reasons the company has decided to keep the AI model unreleased, and does not plan to release it to the public.

However, some might ask that the existence of such a powerful model in itself raises serious concerns. Anthropic is a corporation with its own interests in profit-making and being ahead of the competition. So, what is stopping the company from unleashing an attack on a rival to improve its market position? In the days to come, the company will likely come up with a way to be more transparent with the world about the model and how Anthropic is limiting and monitoring its usage.