Executive brief
Blinko is an open-source personal AI note-taking application that stores chat conversations and messages. An authenticated user can read, modify, or delete another user's entire chat history and messages by simply guessing sequential ID numbers, because the application fails to verify that the requested conversation or message belongs to the attacker's account before processing the request.
Technical details
The vulnerability is an insecure direct object reference (IDOR) in five tRPC procedures (message.list, message.update, message.delete, message.clearAfter, and conversation.clearMessages) that handle user data. Although these endpoints require authentication, they accept caller-supplied conversation or message IDs and perform database operations without validating that the resource belongs to the authenticated user's account. An attacker with any valid account can enumerate sequential integer IDs to discover and access, modify, or delete other users' data. The vulnerability exists in server/routerTrpc/message.ts and server/routerTrpc/conversation.ts. A fix should verify that the accountId associated with the requested resource matches the authenticated user's ID before allowing access.
Affected products
- Blinko Blinko 1.8.7
Timeline
- 2026-09-04: disclosed