"Duplicate chat" is leaking entire conversation

[dd7]

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

The “Duplicate chat” button is available after every model output. As a result, users will assume that it forks the conversation from that point. However, the agent in the duplicated chat knows things that happened after the fork point.

If this feature is merely intended to duplicate the entire chat history, then (a) the button should be made available in one location only, not after every agent response.

Steps to Reproduce

Have the following conversation:

user> Hi, I’d like to do a task.

agent> Sure, what’s the task?

user> OK, just as a test, can you give me the square root of 64?

agent> 8.

Now, after the “Sure, that’s the task?” reply, select “Duplicate chat”. In the duplicated chat, the history will show that the agent does not yet know the task.

Enter

"Sorry I forgot, what exactly was the task I gave you? "

It will say something like

“You haven’t given me a task yet. You said “I’d like to do a task” and then asked for the square root of 64 as a test. What’s the actual task?”

Expected Behavior

In the duplicated chat, which only shows conversation history up to a certain point in the conversation, the agent should have no knowledge of subsequent parts of the conversation.

Operating System

MacOS

Version Information

Version: 2.4.31 (Universal)
VSCode Version: 1.105.1
Commit: 3578107fdf149b00059ddad37048220e41681000
Date: 2026-02-08T07:42:24.999Z
Build Type: Stable
Release Track: Default
Electron: 39.2.7
Chromium: 142.0.7444.235
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Darwin arm64 24.6.0

For AI issues: which model did you use?

Claude Opus 4.6

Does this stop you from using Cursor

No - Cursor works, but with this issue

[deanrie]

Hey, thanks for the detailed report. This is a known issue: the UI only shows history up to the fork point, but the model gets the full conversation.

I see you’re on version 2.4.31. A fix for this bug should’ve shipped after that. Please update to the latest version (Help > Check for Updates) and try again.

If the issue still happens after updating, let me know and we’ll dig in.

[dd7]

Thanks @deanrie . It’s still broken on 2.4.37 (full version info below)

hi I’d like to give you a task

Go ahead — what’s the task?

what’s 7*9?

63

---

Now I “Duplicate Chat” before I say “what’s 7*9”. The new chat looks like this:

hi I’d like to give you a task

Go ahead — what’s the task?

sorry I forgot what I entered – what task did I give you?

You didn’t get to it yet — you said you’d like to give me a task, then asked what 79 is. Still waiting on the task.

---

This seems like a severe bug that needs an urgent hotfix. People will be attempting to control context in a precise way by forking at a chosen point, and it may take them a long time before they realize that Cursor has a bug and in fact the agent knows things they were deliberately trying to conceal.

Version: 2.4.37 (Universal)
VSCode Version: 1.105.1
Commit: 7b9c34466f5c119e93c3e654bb80fe9306b6cc70
Date: 2026-02-12T23:15:35.107Z
Build Type: Stable
Release Track: Default
Electron: 39.2.7
Chromium: 142.0.7444.235
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Darwin arm64 24.6.0

[deanrie]

Thanks for checking and for the detailed repro. I can see the bug also reproduces on 2.4.37, so I’ve passed it to the team to double-check the fix. Looks like something didn’t make it in, or it’s a regression.

[dny_ex]

Same issue and opinion +1