Executive brief
SiYuan is a note-taking and knowledge management application that allows users to organize content in notebooks with privacy controls. A flaw in the file retrieval API allows users with read-only access to bypass notebook visibility restrictions and retrieve private files, including internal configuration, from notebooks explicitly marked as hidden. An attacker who knows the notebook identifier and file path can access sensitive content that should not be visible to them.
Technical details
The vulnerability is a missing authorization check (CWE-862) in the /api/file/getFile endpoint of SiYuan's kernel/api/router.go. The endpoint calls model.CheckAbsPathAccessableByPublishAccess to validate access for read-only roles, but the authorization logic in kernel/model/publish_access.go fails to enforce the Visible:false flag for normal files within hidden notebooks. Instead, it only checks password and disable states. An attacker with the reader role can exploit this by sending a POST request to /api/file/getFile with a known hidden notebook identifier and file path, bypassing visibility restrictions to retrieve private workspace files and internal configuration (e.g., .siyuan/conf.json). The vulnerability has been confirmed by a proof-of-concept test that demonstrates a reader accessing private files in a Visible:false notebook. No patch has been announced as of the advisory date.
Affected products
- SiYuan SiYuan through 3.8.1
Timeline
- 2026-09-04: advisory: CVE-2026-85578 published by NVD
- 2026-08-21: disclosed: GHSA-8ggq-wq3f-vxrw advisory published on GitHub