Anthropic Accidentally Leaks Claude Source Code in Major Security Mistake

Anthropic, the AI company behind Claude, is facing a major security incident after its internal source code was accidentally leaked online.

According to reports from The Verge and Axios, the leak happened during a routine software update for Claude Code. But something went very wrong.

How the Leak Happened

At around 4 AM, Anthropic released an update for Claude Code.

Inside that update, a debugging file was accidentally included. That file contained a large part of Anthropic’s internal source code.

The leaked code reportedly included around 512,000 lines of proprietary software.

A researcher quickly noticed the file and shared it on X (formerly Twitter). From there, things escalated very fast.

The Code Spread Quickly

Within a very short time:

• Millions of people saw posts about the leak
• The code was downloaded and copied
• Repositories appeared across GitHub
• Mirrors were created on other platforms

By the time Anthropic’s team reacted, the code had already spread widely online.

Anthropic Tries to Contain the Leak

Anthropic quickly removed the package and started sending DMCA takedown requests to remove repositories hosting the leaked code.

However, by then, it was already too late. Copies of the code were already widely distributed across the internet.

Developer Response: Rewrites and “Clones”

One unexpected twist came from the developer community.

A developer named Sigrid Jin, known for heavy use of Claude Code, reportedly rebuilt the leaked system from scratch in Python. He published it on GitHub under a new name.

Because it was rewritten and not copied directly, it is considered a new work and harder to remove under copyright rules.

The project quickly gained huge attention online, reaching tens of thousands of stars. Later, the developer also began rewriting it again in Rust.

A Codebase That Cannot Be Fully Removed

Even as Anthropic tries to clean up the leak, the code continues to exist in many forms:

• GitHub repositories
• Mirrors on decentralized platforms
• Rewritten versions inspired by the original

Some copies are now effectively impossible to fully remove from the internet.

Irony in the Situation

What makes the story especially striking is that Anthropic has worked on safety systems designed to prevent AI from leaking sensitive information.

One of their systems is even meant to stop internal data leaks.

But in this case, the leak came from their own software update.

Why This Matters

This incident raises important questions about:

• How AI companies manage internal code
• How easily sensitive data can be exposed
• Whether current security processes are strong enough

It also shows how quickly information can spread online, even when companies try to stop it.

Final Thoughts

A simple debugging mistake turned into one of the most serious AI-related leaks in recent years.

Even with fast takedown efforts, the code had already spread too far to fully control.

The incident is now being widely discussed as a major warning for AI companies about software security and release processes.