[BUG] Context contamination: response about unrelated topic (Python web scraping) in a PHP project session

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

During a Claude Code session working on a PHP trading bot project, Claude suddenly started responding about web scraping with Python — a topic completely unrelated to anything in my project or conversation history.

The response was:

• In English (my project uses French for UI/commits, and I was communicating in French)
• Contained raw unrendered HTML in the output
• About Python web scraping — a technology/topic never used in this project
• Completely unprompted — no question or context leading to this topic

This raises concerns about context contamination between sessions or users.

What Should Happen?

A response relevant to my PHP project and current conversation context.

Error Messages/Logs

Steps to Reproduce

Unable to reproduce — happened spontaneously during a normal session.

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

v2.1.44

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

• I used /clear after the incident, so the conversation log is lost
• The session was otherwise normal before this happened
• The current session (after restart) works correctly with proper context
• This is concerning from a privacy/confidentiality perspective if context from another user's session leaked into mine