Blinko 1.8.7 contains an authorization bypass (IDOR) vulnerability in multiple tRPC procedures (message.list, message.update, message.delete, message.clearAfter in server/routerTrpc/message.ts and conversation.clearMessages in server/routerTrpc/conversation.ts). Although these procedures require authentication, they query the database by caller-supplied conversation or message ID without verifying that the resource belongs to the requesting account. Any authenticated user can therefore read another user's full AI chat history, modify individual message content, and delete or wipe entire conversations by enumerating sequential integer IDs.

Blinko version 1.8.7 contains an Insecure Direct Object Reference (IDOR) vulnerability affecting multiple tRPC procedures including message.list, message.update, message.delete, message.clearAfter, and conversation.clearMessages. While these endpoints require authentication, they fail to verify that the requested resource belongs to the authenticated user, instead trusting caller-supplied conversation or message IDs directly. An attacker with a valid account can exploit this by enumerating sequential integer IDs to access, modify, or delete other users' AI chat histories and conversations. The vulnerability exposes sensitive user data and allows unauthorized data manipulation across user boundaries. The issue was identified in server/routerTrpc/message.ts and server/routerTrpc/conversation.ts source files. A fix appears to have been introduced in version 1.8.8 based on the patched file references in GitHub.