Anthropic limits access to AI model over cyberattack concerns

Anthropic is limiting access to its new AI model after the company said it identified thousands of software vulnerabilities across major systems, raising concerns about potential misuse in cyberattacks.

The new general-purpose model, Anthropic said, also found high-severity vulnerabilities in every major operating system and web browser.

AI has already been widely adopted by hackers to conduct cyberattacks. There was a 72% year-over-year increase in AI-powered cyberattacks, with 87% of global organizations experiencing AI-enabled cyberattacks in 2025, according to AllAboutAI. 

Anthropic expressed concern over what would happen if similar AI capabilities were used by bad actors.

To combat this, Anthropic announced Project Glasswing on Tuesday, a new initiative that brings together more than 40 companies, including Amazon Web Services, Apple, Cisco, Google, JPMorgan, the Linux Foundation, Microsoft and Nvidia.

Project Glasswing will use Claude Mythos Preview's capabilities to defensively find bugs, share the data with its partners and get ahead of threats by patching critical vulnerabilities before bad actors can exploit them.

Decades-old bugs are being discovered 

A zero-day vulnerability is a software bug that can be exploited before anyone with the ability to fix it even knows it exists. Finding and patching them has historically required rare, expensive human expertise, but AI could change the scale and speed of detection. 

Anthropic said the vulnerabilities it finds are “often subtle or difficult to detect.” 

Many of them are 10 or 20 years old, with the oldest found so far being a now-patched 27-year-old bug in OpenBSD — an operating system known primarily for its security, it added. 

It also found a 16-year-old bug in the FFmpeg media processing library, a 17-year-old remote code execution vulnerability in the open-source FreeBSD operating system and numerous vulnerabilities in the Linux kernel.

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Mythos Preview also identified several weaknesses in the world’s most popular cryptography libraries, algorithms and protocols, including TLS, AES-GCM and SSH. 

It added that web applications “contain a myriad of vulnerabilities,” ranging from cross-site scripting and SQL injection to domain-specific vulnerabilities such as cross-site request forgery, which is often used in phishing attacks. 

Anthropic claimed that 99% of the vulnerabilities it found have not yet been patched, “so it would be irresponsible for us to disclose details about them.

Software will emerge more secure, but not overnight 

Anthropic said that this is likely just the beginning of a trend, and the “work of defending the world’s cyber infrastructure might take years,” but AI will help harden software and systems. 

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