CVE-2026-68586

SiYuan before v3.7.3 Content Disclosure via getBacklinkDoc

Published Aug 3, 2026 CVSS 4.0 · 9.2 Critical EPSS < 1% KEV · Not listed
Description
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).

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-36v8-mpjm-8j5r SiYuan: Cross-boundary content disclosure via getBacklinkDoc/getBackmentionDoc (publish mode): reader-reachable rendered DOM of publish-forbidden docs; sibling list endpoints are filtered
History
Type Values Removed Values Added
First Time appeared B3log
B3log siyuan
CPEs cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*
Vendors & Products B3log
B3log siyuan
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Siyuan
Siyuan siyuan
Vendors & Products Siyuan
Siyuan siyuan
Type Values Removed Values Added
Description 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).
Title SiYuan before v3.7.3 Content Disclosure via getBacklinkDoc
Weaknesses CWE-862
References
Metrics cvssV3_1

{'score': 8.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N'}

cvssV4_0

{'score': 9.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Aug 14, 2026, 4:51 PM
Reserved
Jul 31, 2026, 11:56 AM
Status
Deferred
Published
Aug 3, 2026, 2:16 PM
Modified
Oct 23, 2026, 9:10 PM