SiYuan versions before v3.7.4 fail to validate publish-password tier in getGraph and getLocalGraph endpoints, allowing anonymous readers to retrieve block-level content of password-protected documents. Attackers can call these endpoints without supplying a password to read protected document content and the complete reference topology.

Affected: Go: github.com/siyuan-note/siyuan/kernel

**CVE:** This vulnerability corresponds to [CVE-2026-72804](https://nvd.nist.gov/vuln/detail/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:

```go 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 `nod…