Executive brief
SiYuan is a note-taking and knowledge management application that supports a publish mode for sharing content. This vulnerability allows anonymous readers or any user with read access in publish mode to passively receive a live, real-time stream of all document edits—including those marked as password-protected, unpublished, or forbidden—by simply keeping a WebSocket connection open. The attacker gains access to sensitive metadata and content without any active interaction, defeating all publish-access and password protections for edits made while connected.
Technical details
The vulnerability is a missing authorization check (CWE-862) in SiYuan's WebSocket broadcast mechanism used for real-time synchronization. When publish mode is enabled with authentication disabled, the `HandleConnect` function admits anonymous `RoleReader` tokens and registers them in the same broadcast session pool as authenticated clients. The kernel's broadcast functions (`Broadcast`, `broadcastOthers`, etc.) transmit content events—including document transactions with DOM rendering, create/save events, move/rename operations—to all sessions in the pool without applying any publish-access, publish-password, or role-based filtering. The `isPublish` flag exists on sessions but is only used to send a service-closed notice, not to gate content. Because events are pushed directly over WebSocket from the kernel's edit pipeline, they bypass all HTTP-layer publish-access filters. A network-reachable attacker with no privileges can open a WebSocket connection to the publish surface (port 6808) and passively receive unfiltered edits, including metadata and content from password-protected or unpublished documents, as long as they hold the connection open while edits occur. Patch 0.0.0-20260723013612-ba948639d7f6 is available.
Affected products
- siyuan-note siyuan < 0.0.0-20260723013612-ba948639d7f6
Timeline
- 2026-09-03: disclosed: GitHub Security Advisory published
- 2026-07-23: patched: Patch commit ba948639d7f6 available