Hey, thanks for the detailed report.
From your screenshot, it looks like the video’s binary data ended up directly in the prompt body and overflowed the context. The assistant’s reply in that same JSON clearly shows it then picked up completely unrelated project context (health_check_controller.py, OpenSearch, Daily Digests). That matches the “contamination” path you described.
This is a known category of issue. Similar reports are in these threads:
- Data contamination in Cursor conversations: Data contamination in Cursor conversations
- Agent bleed with someone else’s codebase: Agent bleed with someone else's codebase?
Two things that would help the investigation:
- A Request ID from one of the affected chats (top right of the chat > Copy Request ID)
- The models you mentioned, Opus 4.6 thinking and Sonnet 4.5. Did you see this with both, or mostly with one?
As a temporary workaround, avoid pasting direct media file URLs into chat. If you need to reference a video URL, wrap it in backticks or put it in a code block so it’s handled as a string and not resolved.
Let me know if you can grab that Request ID.