CVE-2026-68586: SiYuan before v3.7.3 Content Disclosure via getBacklinkDoc
SiYuan before v3.7.3 fails to apply publish-access filters to the getBacklinkDoc and getBackmentionDoc content endpoints (/api/ref/getBacklinkDoc and /api/ref/getBackmentionDoc). While the corresponding backlink list endpoints filter publish-forbidden documents, the content endpoints (gated only by CheckAuth) do not. A publish-mode reader — including an anonymous reader when publish Basic Auth is disabled — can call these endpoints directly with a publish-forbidden document's ID to retrieve its rendered DOM content and to determine whether the document references a given block (a reference-existence oracle).
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
SiYuanto a version that resolves this vulnerability.Fixed in 3.7.3 - Configuration
Apply publish-access filters to the content endpoints /api/ref/getBacklinkDoc and /api/ref/getBackmentionDoc so that publish-forbidden documents are not retrievable via these endpoints (the issue is that they were gated only by CheckAuth and failed to apply publish-access filters before v3.7.3).
SiYuan API (/api/ref/getBacklinkDoc and /api/ref/getBackmentionDoc) publish-access filter enforcement = enabled
Event History
Frequently Asked Questions
What is the severity of CVE-2026-68586?
The severity of CVE-2026-68586 is high, with a CVSS score of 8.6.
How does CVE-2026-68586 affect SiYuan users?
CVE-2026-68586 allows unauthorized access to sensitive content via the getBacklinkDoc and getBackmentionDoc endpoints.
What versions of SiYuan are affected by CVE-2026-68586?
SiYuan versions prior to 3.7.3 are affected by CVE-2026-68586.
How do I fix CVE-2026-68586?
The fix for CVE-2026-68586 is to upgrade SiYuan to version 3.7.3 or later.
Is CVE-2026-68586 related to other vulnerabilities in SiYuan?
Yes, it is related to access control issues in content disclosure mechanisms within the SiYuan application.