Summary
SiYuan: Publish-boundary bypass via WebSocket broadcast: anonymous readers receive a live unfiltered feed of all edits including protected/forbidden documents (publish mode)
CVE: This vulnerability corresponds to CVE-2026-72810.
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a real-time feed of every edit made in the workspace, including edits to password-protected, publish-forbidden, and unpublished documents.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:
updateAttrswithname=WS_LEAK_SECRET_9931on a block whoserootIDis a password-protected document.- The secret title
WS_SECRET_DOC_7742of a newly created document. - The create event carrying the notebook (box) name
CritChainand 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.
The application does not perform an authorization check before performing a sensitive operation. Typical impact: unauthorized access to restricted functionality or data.
CVE-2026-72810 has a CVSS score of 8.6 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.0.0-20260723013612-ba948639d7f6); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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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.
Frequently Asked Questions
- What is CVE-2026-72810? CVE-2026-72810 is a high-severity missing authorization vulnerability in github.com/siyuan-note/siyuan/kernel (go), affecting versions < 0.0.0-20260723013612-ba948639d7f6. It is fixed in 0.0.0-20260723013612-ba948639d7f6. The application does not perform an authorization check before performing a sensitive operation.
- How severe is CVE-2026-72810? CVE-2026-72810 has a CVSS score of 8.6 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of github.com/siyuan-note/siyuan/kernel are affected by CVE-2026-72810? github.com/siyuan-note/siyuan/kernel (go) versions < 0.0.0-20260723013612-ba948639d7f6 is affected.
- Is there a fix for CVE-2026-72810? Yes. CVE-2026-72810 is fixed in 0.0.0-20260723013612-ba948639d7f6. Upgrade to this version or later.
- Is CVE-2026-72810 exploitable, and should I be worried? Whether CVE-2026-72810 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-72810 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-72810? Upgrade
github.com/siyuan-note/siyuan/kernelto 0.0.0-20260723013612-ba948639d7f6 or later.