CVE-2026-72798: SiYuan Publish-access Filter On RenderAttributeView Leaves Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-mfrj-v65r-979c",
  "modified" : "2026-09-04T20:58:04Z",
  "published" : "2026-09-04T20:58:04Z",
  "aliases" : [ "CVE-2026-72798" ],
  "summary" : "SiYuan: Publish-access filter on renderAttributeView leaves related-database content unfiltered and fails open on non-block first columns",
  "details" : "**CVE:** This vulnerability corresponds to [CVE-2026-72798](https://nvd.nist.gov/vuln/detail/CVE-2026-72798).\n\n### Summary\n\n`renderAttributeView` correctly applies the reader publish-access filter, but the filter's row-accessibility decision is keyed solely to the row's **first cell**, and it never inspects the remaining cells' values. Relation and Rollup cells carry mirrored content from a *different* database, so a row belonging to a published database can hand an anonymous reader the contents of a related database whose host document is hidden, publish-forbidden, or password-protected. Separately, when the first column is not a block value the accessibility check is skipped entirely and the row is returned unchecked.\n\n### Note:\n\nThis is distinct from the previously reported password-tier omission in the same function that concerns the row's own primary block, whereas these two defects concern (a) other cells' related-database content, which no row-level check covers and (b) rows where the first cell is not a block at all. A fix to the row-drop condition alone would close neither.\n\n### Details\n\n`renderAttributeView` applies the filter (`kernel/api/av.go:68`):\n```go\nretDataMap[\"view\"] = model.FilterViewByPublishAccess(c, publishAccess, retDataMap[\"view\"].(av.Viewable))\n```\n\nInside `FilterViewByPublishAccess` (`kernel/model/publish_access.go`):\n```go\nif row.Cells[0].Value.Block != nil {\n    bt = treenode.GetBlockTree(row.Cells[0].Value.Block.ID)\n}\nif bt != nil {\n    if !CheckPathAccessableByPublishIgnore(bt.BoxID, bt.Path, publishIgnore) {\n        row = nil   // drop\n    }\n}\n// every other cell in the row is returned as-is\n```\n\n**(a) Relation and Rollup cells leak the related database.** These value types carry mirrored content, not just references:\n```go\ntype ValueRelation struct { BlockIDs []string; Contents []*Value }\ntype ValueRollup   struct { Contents []*Value }\n```\nThe render pipeline populates them from a different attribute view e.g. `kernel/model/attribute_view.go:2731`:\n```go\nv.GroupVal.Relation.Contents = []*av.Value{ relationDestAv.GetBlockValue(groupValue) }\n```\n`relationDestAv` is a separate database that may live in a hidden, publish-forbidden, or password-protected document. When a published database's row survives the filter (because its column-0 document is public), its Relation and Rollup columns return the related, non-published database's content block text, titles, and mirrored column values. `FilterViewByPublishAccess` performs no publish-access evaluation on `Relation.Contents` or `Rollup.Contents`.\n\n**(b) Fail-open when column 0 is not a block.** `bt` is assigned only when `row.Cells[0].Value.Block != nil`. If the first column is a non-block type (Relation, Text, …) or the row is detached, `bt` remains `nil`, the `if bt != nil` guard is skipped, and the row is returned with no accessibility check at all. Column order is user-reorderable, so any database whose first column is not the document block bypasses row filtering entirely.\n\nVerified at `origin/master` (`eef105683`).\n\n### Proof of Concept\n\nPrecondition: publish mode enabled (default port 6808); anonymous when `Publish.Auth.Enable` is `false`. Two databases: **DB-A** hosted in a published document, **DB-B** hosted in a publish-forbidden or password-protected document, with a Relation column in DB-A pointing at DB-B and containing a distinctive marker value.\n\n**(a) Related-database content disclosure:**\n```\nPOST http://127.0.0.1:6808/api/av/renderAttributeView\n{\"id\":\"<DB_A_AV_ID>\"}\n```\nRows of DB-A are returned (correctly, since its host document is public), and their Relation/Rollup cell `Contents` include DB-B's block text and mirrored column values, despite DB-B's host document being excluded from publishing.\n\n**(b) Fail-open row:**\nReorder DB-A so its first column is a non-block type (or use a detached row), mark its host document publish-forbidden, and request the same endpoint the row is returned without any accessibility evaluation.\n\n*Verification status:* both defects are confirmed by code inspection at `origin/master`. A live demonstration requires a build from HEAD with two linked databases; available on request.\n\n### Impact\n\nAn anonymous reader (publish mode with auth disabled) or any publish `RoleReader` can read content from databases whose host documents are hidden, publish-forbidden, or password-protected, by requesting a *published* database that relates to them. Because relation graphs are commonly used to link a public index to private detail records, this exposes exactly the data the publish boundary is meant to withhold. The fail-open path additionally returns rows with no accessibility check whenever the first column is not a block value, which is a user-controlled layout property. Confidentiality-only.\n\n### Suggested fix\n\nIn `FilterViewByPublishAccess`:\n1. For each retained row, evaluate every `Relation.Contents` and `Rollup.Contents` entry against `CheckBlockIdAccessableByPublishAccess` (including the publish-password tier) and drop or mask entries that fail.\n2. Fail closed: when `row.Cells[0]` has no accessible block (`Value.Block == nil` or `bt == nil`), drop the row rather than returning it unchecked.",
  "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" : "0.0.0-20260724121519-426991d155c0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-mfrj-v65r-979c"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-72798"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/siyuan-note/siyuan/commit/426991d155c0c7c3a9e71badd6761eddfa8aad5b"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/siyuan-note/siyuan"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/siyuan-before-information-disclosure-via-renderattributeview"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-862" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-04T20:58:04Z",
    "nvd_published_at" : null
  }
}