Anthropic’s special Claude Code CLI tool had its complete TypeScript source code inadvertently exposed due to a misconfiguration in npm package. A security researcher found a leaked .map file that pointed to the clear code stored on Anthropic’s own cloud.

By infosecbulletin
/ Wednesday , November 11 2026
Microsoft has shared its updates for November 2026. These updates fix 1,093 new flaws in Windows, Office, SQL Server, SharePoint,...
Read More
By infosecbulletin
/ Wednesday , November 11 2026
Barracuda has confirmed active exploitation of security flaws affecting its Email Security Gateway (ESG), warning that attackers could combine two...
Read More
By infosecbulletin
/ Tuesday , November 10 2026
Apple, SAP, and Ivanti have published security updates that fix several flaws with messaging, Bluetooth, enterprise servers, and endpoint management...
Read More
By infosecbulletin
/ Tuesday , November 10 2026
A jailbroken AI has been attacking a European telecom company and 13 companies using its data center and cloud for...
Read More
By infosecbulletin
/ Tuesday , November 10 2026
Cyberattacks are rising around the world, including ransomware, malware, data leaks, and hacked websites. These events show how complex and...
Read More
By infosecbulletin
/ Tuesday , November 10 2026
IBM patched 208 security flaws in its API Connect platform. The CVE records released out on November 7, 2026. Among...
Read More
By infosecbulletin
/ Sunday , November 8 2026
New ransomware actions in 2026 show more variety in cybercrime, with some groups claimed over 100 victims. The ransomware attack...
Read More
By infosecbulletin
/ Sunday , November 8 2026
Cyberattacks are rising around the world, including ransomware, malware, data leaks, and hacked websites. These events show how complex and...
Read More
By infosecbulletin
/ Saturday , November 7 2026
A major system failure has brought customer-facing banking services to a standstill at 128 shinkin banks across western Japan, leaving...
Read More
By infosecbulletin
/ Friday , November 6 2026
Cyberattacks are rising around the world, including ransomware, malware, data leaks, and hacked websites. These events show how complex and...
Read More
Security researcher posted on x saying that
“Claude Code source code has been leaked via a map file in their npm registry!”.
The post quickly got people in the AI community talking. It got almost 10 million views and 1,500 comments.

It seems that Anthropic hurried to take down the npm package. But it was too late. Many GitHub users had already shared copies of the project.
The .map files are often used by developers to fix software programs. These plain text files work like a small map of the original code, helping developers find where the errors happen. But .map files usually don’t have the complete source code.