SiYuan: Graph endpoints omit the publish-password tier: anonymous readers receive block-level content of password-protected documents

CVE: This vulnerability corresponds to CVE-2026-72804.

Summary

getGraph and getLocalGraph filter reader sessions against the visibility tier only and never check the publish password. Password-protected documents are Visible = true, so their graph nodes survive the filter and graph nodes are block-level and carry the block's actual content. An anonymous reader who has never supplied a document's password can therefore retrieve that document's per-block content and its reference/backlink topology. Both endpoints are CheckAuth-only, so they are reachable by the publish RoleReader token and by the anonymous account when Publish.Auth.Enable is false.

Details

Both handlers filter with the invisible-tier set only:

publishIgnore := model.GetInvisiblePublishAccess(publishAccess)   // Visible tier ONLY
nodes, links = model.FilterGraphByPublishIgnore(publishIgnore, nodes, links)

FilterGraphByPublishIgnore (kernel/model/publish_access.go:849) drops a node only when !CheckPathAccessableByPublishIgnore(node.Box, node.Path, publishIgnore). There is no password evaluation anywhere in the graph code grepping graph.go for CheckPublishAuthCookie or password returns nothing.

Because password-protected documents are Visible = true, their nodes pass the filter unchanged.

The nodes carry content, not just titles. genTreeNodes emits one node per block, and nodeTitleLabel sets node.Title = node.Label = block.Content (kernel/model/graph.go:673-678). So each surviving node exposes the block's text.

This is materially broader than the by-design listing behaviour: listDocsByPath intentionally exposes protected document titles (protected means "publicly visible, password required to access"), but the graph endpoints expose per-block content and the full link/reference topology, which listing never does.

Verified at origin/master: FilterGraphByPublishIgnore contains only the CheckPathAccessableByPublishIgnore call; graph.go contains no password check; both routes are registered CheckAuth without CheckAdminRole.

Proof of Concept

Precondition: publish mode enabled (default port 6808); anonymous when Publish.Auth.Enable is false, otherwise any publish reader account. A document is marked protected (visible, password set) and contains blocks with distinctive content. No password is supplied in any request below.

Targeted: one protected document's content and reference structure:

POST http://127.0.0.1:6808/api/graph/getLocalGraph
{"id":"<PROTECTED_DOC_ID>"}

Returns nodes whose Title/Label contain the protected document's per-block content, plus its links/backlinks.

Workspace-wide: every protected document:

POST http://127.0.0.1:6808/api/graph/getGraph
{}

Returns block-level nodes for every protected document in the workspace, together with the complete link graph.

Control: requesting the same document through the normal content path returns the password placeholder confirming the password gate is enforced elsewhere and omitted here.

Impact

An anonymous reader (publish mode with auth disabled) or any publish RoleReader can read the block-level content of every password-protected document in the workspace, plus the full reference/backlink topology, without ever supplying a password. This defeats the publish-password control for the graph subsystem. Confidentiality-only, no modification.

Suggested fix

Extend the graph filter to evaluate the password tier in addition to visibility: in FilterGraphByPublishIgnore, drop a node unless the document's publish password is unset or the caller presents a valid publish-auth cookie for it (password == "" || CheckPublishAuthCookie(...)), matching the sibling filters that enforce both tiers. Consider also excluding block content from node Title/Label for reader sessions, so the graph conveys structure without document text.