Agent browser_tabs attaches to Home/empty-window Browser Tabs from a different project workspace

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Follow-up: sanitized logs + session IDs + wrong-path ENOENT

Data sharing on. Strongest log evidence for cross-workspace browser / MCP FS bleed.

Cross-workspace signals

  1. From a project agent chat, browser viewId was stable-browser-session/b23abea01bc4771017b008369920af3f — that hex is the Home/empty-window workspaceId, not the project’s.
  2. Project MCP FileSystem Writer (workspaceId=c63b395f862a583cf684909c2973e535) hit:
    ENOENT … open '/Users/johnsolly/.cursor/projects/Users-johnsolly-cursor-worktrees-stocktextalerts-sfeo/mcps/cursor-ide-browser~staging/tools/browser_click.json'
    i.e. tried to write cursor-ide-browser staging tools into a third project’s path (stocktextalerts worktree) while this chat was on jsolly-website.

Session / identity (data sharing on)

  • machineId: 45f9fb3f-e7a9-4793-a235-3a7bb93e4e3f
  • Cursor: 3.13.21 (55434bd8062ece6fee083b82beed2aee42d253f0) Darwin arm64
  • Log session folder: ~/Library/Application Support/Cursor/logs/20260727T152911/
  • Home/empty-window workspaceId: b23abea01bc4771017b008369920af3f
  • Project workspaceId (writers): c63b395f862a583cf684909c2973e535
  • empty-window composerId: d174e224-0460-47e0-9ea0-763af6aa41df
  • jsolly-website composerId: 5acf3d63-e855-475f-80d3-765ec4494774
  • Sample requestIds (wb62 / this chat): ea519e6d-beca-48ec-a1cc-0f2014441f94, 39c62806-5a07-4e7b-a817-a2f6b664a5c8
  • Sample requestIds (wb58 / empty-window): 01ecc7d9-bae9-4492-839d-1da5719701eb, 5f3e45fc-f834-4f42-8e83-2e74cb80e63f, a85646b1-270f-459a-9cda-acc3b8fa91e0

Attachments focused on this bug

00-SESSION-IDS.txt
04-KEY-EXCERPTS.txt
02-wb65-McpFileSystemWriter-ENOENT-wrong-path.log
02-wb64-McpFileSystemWriter.log
01-empty-window-wb58-McpFileSystemWriter-b23abe.log
cursor-browser-bugs-logs-sanitized.zip

Related: 166850, 165025, 166064.