CVE-2026-72804: SiYuan Graph Endpoints Omit The Publish-password Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-vpjw-wf5h-cgpq",
  "modified" : "2026-09-03T22:52:58Z",
  "published" : "2026-09-03T22:52:58Z",
  "aliases" : [ "CVE-2026-72804" ],
  "summary" : "SiYuan: Graph endpoints omit the publish-password tier: anonymous readers receive block-level content of password-protected documents",
  "details" : "**CVE:** This vulnerability corresponds to [CVE-2026-72804](https://nvd.nist.gov/vuln/detail/CVE-2026-72804).\n\n### Summary\n\n`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`.\n\n### Details\n\nBoth handlers filter with the invisible-tier set only:\n\n```go\npublishIgnore := model.GetInvisiblePublishAccess(publishAccess)   // Visible tier ONLY\nnodes, links = model.FilterGraphByPublishIgnore(publishIgnore, nodes, links)\n```\n\n`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.\n\nBecause password-protected documents are `Visible = true`, their nodes pass the filter unchanged.\n\n**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.\n\nThis 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.\n\nVerified at `origin/master`: `FilterGraphByPublishIgnore` contains only the `CheckPathAccessableByPublishIgnore` call; `graph.go` contains no password check; both routes are registered `CheckAuth` without `CheckAdminRole`.\n\n### Proof of Concept\n\nPrecondition: 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.\n\n**Targeted: one protected document's content and reference structure:**\n```\nPOST http://127.0.0.1:6808/api/graph/getLocalGraph\n{\"id\":\"<PROTECTED_DOC_ID>\"}\n```\nReturns nodes whose `Title`/`Label` contain the protected document's per-block content, plus its links/backlinks.\n\n**Workspace-wide: every protected document:**\n```\nPOST http://127.0.0.1:6808/api/graph/getGraph\n{}\n```\nReturns block-level nodes for every protected document in the workspace, together with the complete link graph.\n\n**Control:** requesting the same document through the normal content path returns the password placeholder confirming the password gate is enforced elsewhere and omitted here.\n\n### Impact\n\nAn 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.\n\n### Suggested fix\n\nExtend 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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/siyuan-note/siyuan/kernel"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.0.0-20260724091654-82e9ded423e4"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-vpjw-wf5h-cgpq"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-72804"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/siyuan-note/siyuan/commit/82e9ded423e45eabcc96010abd30c0f96bfe0323"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/siyuan-note/siyuan"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/siyuan-before-authentication-bypass-via-graph-endpoints"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-200", "CWE-862" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-03T22:52:58Z",
    "nvd_published_at" : null
  }
}