CVE-2026-72807: SiYuan Second-order SSTI To Arbitrary SQL Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-x67c-8pwr-m8g3",
  "modified" : "2026-09-03T22:49:31Z",
  "published" : "2026-09-03T22:49:30Z",
  "aliases" : [ "CVE-2026-72807" ],
  "summary" : "SiYuan: Second-order SSTI to arbitrary SQL via attribute-view template column (queryBlocks): malicious imported package executes SQL on victim kernel",
  "details" : "**CVE:** This vulnerability corresponds to [CVE-2026-72807](https://nvd.nist.gov/vuln/detail/CVE-2026-72807).\n\n### Summary\n\nAttribute-view (AV) template columns are live-evaluated on every render and expose the `queryBlocks` template function, which runs raw SQL on the read-write database handle (`SelectBlocksRawStmt`, using `?`→argument string substitution rather than parameter binding). AV mutations are admin-gated, so this is not directly reader-injectable but it is a second-order vector: an attacker distributes a SiYuan document or AV package whose template column contains `.action{queryBlocks \"<arbitrary SQL>\"}` when a victim imports the package and renders the AV, the attacker's SQL executes on the victim's kernel (read and, via statement stacking, write).\n\n### Details\n\nDoc-level `{{…}}` templates are rendered at insert-time and become static, so they are not re-evaluated on reader view. The residual is AV template columns, which are live-evaluated at render. `queryBlocks` passes its argument to `SelectBlocksRawStmt` with `?`→arg string substitution, not a bound parameter, on the main read-write handle (`88250/go-sqlite3` fork, statement-stacking capable) so an attacker-controlled template argument becomes arbitrary SQL.\n\nThe SSTI surface is otherwise hardened: `BuiltInTemplateFuncs` deletes `env`, `expandenv`, and `getHostByName` so there is no environment/host/file/exec SSTI. `queryBlocks`-to-SQL is the remaining live-evaluated sink.\n\n### Proof of Concept\n\nAn AV template column set to `.action{queryBlocks \"<sql>\"}` executes `<sql>` against the read-write handle when the AV is rendered. Delivered second-order: a shared/imported document or AV package carrying such a column runs the embedded SQL on any kernel that imports and renders it.\n\n### Proof of Concept\n\nReproduced on a live instance.\n\n**1. Host doc + AV (admin, 6806):**\n```\nPOST /api/filetree/createDocWithMd {notebook, path:\"/ssti-poc\", markdown:\"host\"}  → DOC\nPOST /api/av/renderAttributeView   {id:\"<AV>\"}   # materializes the AV\n```\n\n**2. Plant the malicious template column (one performTransactions call):**\n```json\n{\"reqId\":1,\"session\":\"poc\",\"transactions\":[{\"doOperations\":[\n  {\"action\":\"addAttrViewCol\",\"avID\":\"<AV>\",\"id\":\"<COL>\",\"name\":\"tpl\",\"type\":\"template\"},\n  {\"action\":\"updateAttrViewColTemplate\",\"avID\":\"<AV>\",\"id\":\"<COL>\",\"type\":\"template\",\n   \"data\":\".action{range queryBlocks \\\"SELECT * FROM blocks WHERE root_id='<PROTECTED_DOC_ID>'\\\"}.action{.Markdown} .action{end}\"},\n  {\"action\":\"insertAttrViewBlock\",\"avID\":\"<AV>\",\"isDetached\":true}\n]}]}\n```\n\n**3. Trigger (render evaluates the template):**\n```\nPOST /api/av/renderAttributeView {id:\"<AV>\"}\n```\nResult: the template cell renders `## LockedSection TOP_SECRET…` the `queryBlocks` SQL executed and returned the password-protected document's content, arbitrary SQL via template reading across the publish/password boundary. `queryBlocks` uses `?`→arg string substitution (not parameterized), so UNION and stacked writes are also possible. Delivered second-order, the same column executes on any kernel that imports and renders the AV.\n\n### Impact\n\nAn attacker who gets a victim to import a crafted document/AV package and render it achieves arbitrary SQL execution on the victim's kernel cross-notebook read and via stacking, write. Precondition is content delivery plus render (import of an attacker-supplied package), which bounds severity to Medium. Not directly reachable by an anonymous reader (AV creation is admin-gated); the injection travels in stored/imported template content.\n\n### Suggested fix\n\nParameterize `queryBlocks` bind the argument rather than substituting it into the SQL string or restrict the template function set available in AV columns as was done for the doc-template functions. Treat imported template content as untrusted at render time.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/siyuan-note/siyuan/kernel"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.0.0-20260723035036-0a176345e02a"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-x67c-8pwr-m8g3"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-72807"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/siyuan-note/siyuan/commit/0a176345e02a0d19bdc7762e50e0b92002087d20"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/siyuan-note/siyuan"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/siyuan-before-sql-injection-via-queryblocks-template"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1336", "CWE-89" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-03T22:49:30Z",
    "nvd_published_at" : null
  }
}