CVE-2026-72810: SiYuan: WebSocket leak bypasses publish access control

**CVE:** This vulnerability corresponds to [CVE-2026-72810](https://nvd.nist.gov/vuln/detail/CVE-2026-72810). ### Summary WebSocket sessions established through the publish surface (port 6808, `RoleReader` anonymous when `Publish.Auth.Enable` is `false`) are added to the same broadcast session pool as authenticated sessions. The kernel's broadcast functions push content events transactions carrying block DOM, document save/create, move/rename to every session in the pool with no role or publish-access filtering. As a result, an anonymous reader who holds a WebSocket connection open passively receives a real-time feed of every edit made in the workspace, including edits to password-protected, publish-forbidden, and unpublished documents. Because these events are delivered over the push channel and never pass through an HTTP handler, none of the publish-access filters that gate the HTTP endpoints apply. ### Details **Session admission.** `HandleConnect` admits the injected `RoleReader` publish token, and the session is registered via `AddPushChan` into the same `sessions` pool used for authenticated clients. **Unfiltered broadcast.** The broadcast functions (`Broadcast`, `broadcastOthers`, `broadcastOtherAppMains`, …) write to every session in the pool with no role or publish-access check. The `isPublish` flag on a session is consulted only to send the "service closed" notice it is never used to gate content. Content events are pushed via `PushModeBroadcast → Broadcast()`, so transactions (with rendered block DOM), `savedoc`/create, and `moveDoc`/rename events reach the publish reader's socket unfiltered. **No HTTP filter applies.** This is a push channel, the events originate from the kernel's own edit pipeline and are broadcast directly to open sockets. They never traverse an HTTP handler, so the publish-access filters that gate the HTTP content endpoints (and the incomplete/missing filters reported separately on those endpoints) are not in the path at all. The WebSocket route (`/ws`) is `CheckAuth`-only, which the publish `RoleReader` token satisfies. ### Proof of Concept Reproduced on a local instance (SiYuan running locally, publish mode enabled on port 6808, publish Basic Auth disabled). An anonymous client (no token, no password) opens `wss://127.0.0.1:6808/ws` and holds it open while an administrator edits documents in the workspace. The anonymous socket received, in real time and unfiltered: - `updateAttrs` with `name=WS_LEAK_SECRET_9931` on a block whose `rootID` is a **password-protected** document. - The secret title `WS_SECRET_DOC_7742` of a newly created document. - The create event carrying the notebook (box) name `CritChain` and the document path. No HTTP request was made beyond the WebSocket upgrade; the content arrived over the push channel. ### Impact An anonymous reader (publish mode with auth disabled) or any publish `RoleReader` who merely holds a WebSocket connection open receives a live feed of every edit an administrator makes: block DOM, attributes, titles, notebook names, and document structure, including for password-protected, publish-forbidden, and unpublished documents. This defeats the publish-access and publish-password boundaries entirely for any content edited while the socket is open. The precondition is trivial: an administrator active in the workspace while the anonymous socket is connected. Confidentiality-only (passive disclosure); the channel is receive-only for the reader. Encrypted-notebook content follows the same broadcast path if edited while unlocked. ### Suggested fix Filter broadcasts by session before writing: for any session flagged `isPublish`, apply the same publish-access/publish-ignore/publish-password checks used on the HTTP content path before pushing a content event, or exclude publish sessions from content broadcasts entirely and deliver only the events a publish viewer is authorized to see. The `isPublish` flag is already present on the session; it should gate content, not only the service-closed notice.

An attacker discovers a SiYuan publish instance exposed on port 6808 with `Publish.Auth.Enable=false` (default-permissive or a common misconfiguration for "quick sharing"). They open a WebSocket connection to `wss://target:6808/ws` with no credentials — `HandleConnect` admits them as an anonymous `RoleReader` and registers the session into the shared broadcast pool. The attacker holds the connection open indefinitely and passively logs every pushed event. As an administrator works in the workspace over the following hours or days — editing password-protected compliance documents, creating a new document with sensitive credentials in the title, renaming notebooks — the attacker's socket silently receives the full block DOM, titles, and document-structure events for all of it, with zero indication in HTTP logs that anything was accessed. The attacker reconstructs sensitive content entirely from the push stream without ever making an authorized HTTP request.