SiYuan: Embedded (transclusion) block content is returned without publish-access filtering, leaking private and password-protected document content to anonymous readers

Overview

CVE: This vulnerability corresponds to CVE-2026-72795.

Summary

/api/block/getBlockDOMWithEmbed and /api/block/getBlockDOMsWithEmbed gate only the requested block against publish access. The blocks pulled in by that block's embed (transclusion) query are inlined into the returned DOM with no publish-access check at all, so a reader who requests a legitimately-published block containing an embed query receives the content of every block that query matched including blocks in hidden, forbidden and password-protected documents.

The dedicated embed endpoint getEmbedBlock filters these same results for reader roles. The DOM-with-embed path does not.

Details

The leak path. getBlockDOMWithEmbed → GetBlockDOMsWithEmbedInBox → resolveEmbedContentInBox (kernel/model/block.go:976). That function walks the tree for NodeBlockQueryEmbed, extracts the embed SQL, executes sql.SelectBlocksRawStmtInBox(stmt, ...), builds embedContents from each matched block's content HTML, and inlines the result via SetIALAttr("embed-content", ...).

resolveEmbedContentInBox takes no publishAccess parameter and contains no filtering: FilterEmbedBlocks, CheckBlockIdAccessableByPublishAccess, CheckPathAccessable, publishAccess and IsReadOnlyRoleContext all return zero matches in that function and its call path. The top-level gate therefore passes on the requested block, and the response body carries content the reader has no access to.

Embed queries in published documents routinely span the entire workspace by design, dashboard documents, "all my TODOs" aggregations, tag or attribute rollups. The reader does not need to construct anything: requesting an already-published document that contains such an embed is sufficient. If the publish frontend renders embedded blocks through this endpoint, the disclosure occurs passively during normal viewing of any published document containing an embed block.

Guarded sibling. getEmbedBlock (kernel/api/router.go:212), which is also reader-reachable and returns embed query results, applies model.FilterEmbedBlocksByPublishAccess(c, publishAccess, blocks) for reader roles (kernel/model/search.go:38). The same class of data is filtered there and unfiltered here.

Scope note. A prior review of getBlockDOMsWithEmbed confirmed that the per-id publish gate is correctly applied to the requested ids. That observation is accurate and is not in dispute, this report concerns the embedded blocks resolved downstream in resolveEmbedContentInBox, which are not covered by that gate.

Proof of Concept

Precondition: publish mode enabled (default port 6808); anonymous when Publish.Auth.Enable is false, otherwise any publish reader account. A published document containing an embed query whose results include at least one block in a non-published or password-protected document.

POST http://127.0.0.1:6808/api/block/getBlockDOMWithEmbed
{"id":"<id of a published block containing an embed query>"}

→ 200
   The returned DOM contains embed-content attributes carrying the
   content HTML of blocks in documents the reader has no publish
   access to.

Differential check against the filtered sibling, using the same reader session and the same underlying query:

POST http://127.0.0.1:6808/api/search/getEmbedBlock
{"stmt":"<the same embed query>"}

→ 200, results filtered by FilterEmbedBlocksByPublishAccess

The filtered endpoint withholds the private blocks; the DOM endpoint returns their content.

The plural route behaves identically for each requested id:

POST http://127.0.0.1:6808/api/block/getBlockDOMsWithEmbed
{"ids":["<published block containing an embed query>"]}

Impact

An anonymous reader in publish mode or any publish RoleReader can read the content of blocks in documents that are not published, are marked hidden or forbidden, or are protected by a publish password, by requesting a published block that transcludes them. Because embed queries in aggregation-style published documents commonly match across the whole workspace, the volume of exposed content is bounded only by what the author's embed queries happen to match, not by anything under the reader's control being unusual. Confidentiality-only; no integrity or availability impact.

Suggested fix

Thread the request's publishAccess context into resolveEmbedContentInBox and, when IsReadOnlyRoleContext holds, drop any matched block failing CheckBlockIdAccessableByPublishAccess and the password-tier check before its content is written into embed-content mirroring the treatment getEmbedBlock already gives the same data via FilterEmbedBlocksByPublishAccess.

Affected packages

• github.com/siyuan-note/siyuan/kernel < 0.0.0-20260725125659-1ca1c3c9d94b

Remediation

Upgrade to a patched release:

• github.com/siyuan-note/siyuan/kernel 0.0.0-20260725125659-1ca1c3c9d94b