CVE-2026-72795

SiYuan's publish-mode endpoints /api/block/getBlockDOMWithEmbed and /api/block/getBlockDOMsWithEmbed (a missing-authorization flaw, CWE-862) enforce publish-access checks only on the block explicitly requested, while blocks pulled in by that block's embed (transclusion) query are inlined into the response with no publish-access filtering at all. An anonymous reader (when Publish.Auth.Enable is false) or a read-only RoleReader token triggers the leak simply by requesting an already-published document that contains an embed block; no crafted request or user interaction is needed, and the disclosure can occur passively during normal viewing if the publish frontend renders embeds through this endpoint. The attacker gains the HTML content of every block matched by the embed query, including blocks inside hidden, access-forbidden, and password-protected documents, so confidential notes outside the published scope can be exposed. Any SiYuan deployment serving published documents that contain embed blocks — commonly dashboards, TODO aggregations, or tag/attribute rollups whose queries span the whole workspace — is affected. No public proof-of-concept or in-the-wild exploitation is known; EPSS is 0.2% and the issue is not in CISA KEV.

What to do: Upgrade SiYuan to the latest available release and check the project's release notes for a fix adding publish-access filtering to getBlockDOMWithEmbed/getBlockDOMsWithEmbed (no fixed version number is available in the data). Until patched, audit published documents for embed-block queries that reach hidden, forbidden, or password-protected documents and restrict those queries to published content; enabling publish authentication limits anonymous exposure but authenticated readers remain affected. After patching, re-test reader and anonymous access to confirm embedded private blocks are no longer returned.