SiYuan EUVD-2026-88560

Requires that the target SiYuan instance has the publish feature enabled and is serving content to publish readers (read-only role context, IsReadOnlyRoleContext) - the vulnerable code path only fires for that role. The attacker must first obtain an unrendered attribute-view (database) identifier through a related endpoint to supply as avID. Exploitation is limited to leaking detached-row image asset paths and filenames from databases the publish configuration should have excluded; it does not expose image binaries, other row data, or writeable access. Instances not using publish mode, or that do not expose the publish endpoint to untrusted readers, are not exposed.

This is a genuine but modest-severity information-disclosure flaw. The vendor CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N, base 6.9) indicates a network-reachable, low-complexity, unauthenticated flaw with only LOW confidentiality impact and no integrity/availability effect - consistent with CWE-200 and the description, which limits the leak to image asset paths and filenames rather than image contents or database records. No EPSS score, no CISA KEV listing, and no public POC were provided; per the precision rules this is 'no public exploit identified at time of analysis.' The vendor patch (commit 48229dc7) is confirmed available and adds a top-level publish-access gate plus a regression test, and the finding was reported by VulnCheck with a GitHub Security Advisory (GHSA-j9p6-5639-gf4f), so the vulnerability itself is well-substantiated. The practical caveat that tempers the raw score: exploitation only matters when SiYuan's publish feature is active and exposing databases to publish readers, and the leak is metadata (paths/filenames), not the assets themselves. Net: real and worth patching, but not an urgent widespread-exploitation priority - a high-confidence, low-impact issue rather than a high-CVSS-but-fictional one.

An operator publishes a SiYuan workspace, granting publish readers access to a subset of notebooks/databases. A publish reader (or anyone who can reach the public publish endpoint) obtains an unrendered attribute-view (database) identifier via a related endpoint, then calls getCurrentAttrViewImages with that avID to retrieve image asset paths and filenames belonging to detached rows in databases the rendering endpoint would otherwise deny. No public POC is referenced, but the patched regression test demonstrates the exact leak path.