CVE-2026-68586: SiYuan getBacklinkDoc/getBackmentionDoc authorization bypass in publish mode

CVE-2026-68586 · Severity: high · CVSS 8.6 · Published 2026-09-03

SiYuan is a local-first note-taking application that supports publish mode to share content selectively. Two API endpoints—getBacklinkDoc and getBackmentionDoc—return the rendered content of notes marked as publish-forbidden to anonymous readers or publish-mode users when authentication is disabled. This bypasses administrator-configured access controls and discloses private note content that should remain hidden.

Technologies: github.com/siyuan-note/siyuan/kernel (Go), SiYuan. Vendors: Go, SiYuan.

Quick answers

Is CVE-2026-68586 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-68586 being exploited in the wild.
How severe is CVE-2026-68586?
High severity, with a CVSS score of 8.6, published 3 September 2026.
Which products and versions are affected?
github.com/siyuan-note/siyuan/kernel (Go) < 0.0.0-20260721014413-f45749a7ef6e, SEMVER:introduced=0,fixed=0.0.0-20260721014413-f45749a7ef6e; SiYuan before 0.0.0-20260721014413-f45749a7ef6e.
Is there a fix for CVE-2026-68586?
Yes. github.com/siyuan-note/siyuan/kernel (Go): upgrade to 0.0.0-20260721014413-f45749a7ef6e or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-68586 attacked?
It is attacked over the network.
Am I affected by CVE-2026-68586?
Check whether you run github.com/siyuan-note/siyuan/kernel (Go) or SiYuan at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • github.com/siyuan-note/siyuan/kernel (Go): upgrade to 0.0.0-20260721014413-f45749a7ef6e or later
    go get github.com/siyuan-note/siyuan/kernel@v0.0.0-20260721014413-f45749a7ef6e

Technical details

The vulnerability is a missing authorization check (CWE-862) in two backlink API endpoints. The list endpoints (getBacklink, getBacklink2) correctly apply a FilterPathsByPublishAccess filter before returning document paths, but the content endpoints (getBacklinkDoc, getBackmentionDoc) omit this check and return rendered HTML blocks (Backlink.DOM) from any document if called with a valid refTreeID and defID. Both endpoints are gated by CheckAuth only, making them reachable to anonymous users when Publish.Auth.Enable is false or to any publish RoleReader token. An attacker must supply refTreeID (the forbidden document ID) and defID (a block it references); if the forbidden document references any public content, defID is discoverable and only refTreeID need be supplied. No admin role, CSRF token, or write permission is required. Impact is confidentiality-only; no data modification is possible. The fix requires applying the same publish-access filtering logic from getBacklink/getBacklink2 to the content endpoints, including CheckPathAccessableByPublishIgnore and publish-password cookie checks.

Affected products

  • SiYuan SiYuan before 0.0.0-20260721014413-f45749a7ef6e

Identifiers

  • CVE-2026-68586
  • GHSA-36v8-mpjm-8j5r
  • GO-2026-6379

Timeline

  • 2026-09-03: disclosed: GitHub Advisory GHSA-36v8-mpjm-8j5r published
  • 2026-07-21: patched: Patched version 0.0.0-20260721014413-f45749a7ef6e released

References

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