CVE-2026-72796: SiYuan Remote Code Execution Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-fgmr-7w36-9qfq",
  "modified" : "2026-09-04T21:02:22Z",
  "published" : "2026-09-04T21:02:22Z",
  "aliases" : [ "CVE-2026-72796" ],
  "summary" : "SiYuan: Static-file routes bypass the publish-access controls enforced on the REST API, exposing templates, snippets and export artifacts to anonymous readers",
  "details" : "**CVE:** This vulnerability corresponds to [CVE-2026-72796](https://nvd.nist.gov/vuln/detail/CVE-2026-72796).\n\n### Summary\n\nSeveral static-file routes in the server mux (`kernel/server/serve.go`) are registered with `CheckAuth` only and serve directories directly, without the publish-access checks, sensitive-path blocklist, or `refuseToAccess` rules that the REST API applies to the same data. They are therefore reachable by the publish `RoleReader` token and by the anonymous account when `Publish.Auth.Enable` is `false`.\n\nMost notably, `/templates/` serves `data/templates` a directory the REST file API explicitly refuses to serve to non-administrators.\n\n### Details\n\n| Route | Registration | Guard | Exposed to a reader |\n|---|---|---|---|\n| `/templates/*` (line 424) | `Group(\"/templates/\", model.CheckAuth).Static(\"\", data/templates)` | none beyond path cleaning | the templates directory |\n| `/snippets/*` (line 434) | `CheckAuth` | blocks only `conf.json` | any snippet's JS/CSS content by name |\n| `/widgets/`, `/plugins/`, `/emojis/` (409/414/419) | `Group(CheckAuth).Static(dir)` | none | whole directory trees |\n| `/export/*` (line 320) | `Group(\"/export/\", CheckAuth)` | traversal, sensitive-path and DEK guards: **no publish check** | export artifacts (PDF/HTML/DOCX/CSV) |\n\n**`/templates/` directly contradicts an existing control.** The REST file path runs `refuseToAccess` (`kernel/api/file.go:551-553`), which explicitly returns 403 for `data/templates/` to non-administrators the project has already decided readers must not read templates. The `/templates/` static route serves that same directory to any `RoleReader`, with no `IsSensitivePath` check, no publish-access check, and no `refuseToAccess`. Templates are user-authored Markdown documents containing template/Sprig syntax and are not covered by publish-access controls. `gin`'s `.Static` disables directory listing, so a filename is required but the contradiction with `refuseToAccess` is the defect.\n\n**`/export/` versus `/assets/`.** `/assets/*path` (line 692) correctly gates non-administrators via `CheckAbsPathAccessableByPublishAccess`, plus `IsSensitivePath` and encrypted-asset handling. `/export/` carries traversal, sensitive-path and DEK guards but no publish-access check, so a reader can retrieve export artifacts of arbitrary documents, including private ones. Artifact naming is mixed, some use a random export ID, but code and CSV exports use the document name (`export/code/<name>`, `export/csv/<name>/<name>.csv`), which a reader can derive from `listDocsByPath` titles while the artifact exists. This path is therefore conditional.\n\n**Confirmed correctly gated, for contrast:** `/assets/*` (publish-gated), `/history/*` and `/repo/diff/*` (`CheckAdminRole`), `/debug/pprof/*` (disabled in production builds), `/public/` (intentionally public).\n\nAll four routes above were verified to carry `CheckAuth` only, no `CheckReadonly`, no `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.\n\n**Templates: served despite the REST API refusing them:**\n```\nGET http://127.0.0.1:6808/templates/<template-file>.md\n→ 200, template content\n```\nThe equivalent REST request is refused:\n```\nPOST http://127.0.0.1:6808/api/file/getFile\n{\"path\":\"data/templates/<template-file>.md\"}\n→ 403 (refuseToAccess)\n```\nThe same reader session obtains the file through the static route.\n\n**Snippets:**\n```\nGET http://127.0.0.1:6808/snippets/<snippet-name>.js\n→ 200, snippet source\n```\n\n**Export artifacts (conditional on a predictable name while the artifact exists):**\n```\nGET http://127.0.0.1:6808/export/csv/<doc-name>/<doc-name>.csv\n→ 200, exported content of a document the reader has no publish access to\n```\n\n### Impact\n\nAn anonymous reader (publish mode with auth disabled) or any publish `RoleReader` can read user-authored template documents that the REST API explicitly withholds from non-administrators, snippet source (JS/CSS), and the contents of the widgets, plugins and emoji directories. Where an export artifact exists under a derivable name, they can additionally retrieve exported content of documents outside their publish scope. Confidentiality-only.\n\n### Suggested fix\n\nApply the same treatment these routes' REST counterparts already receive: for non-administrator roles, enforce publish-access scoping plus `IsSensitivePath` and the `refuseToAccess` blocklist on the static routes, mirroring `/assets/*`. Alternatively, block `/templates/`, non-public `/snippets/`, and `/export/` for reader roles entirely.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/siyuan-note/siyuan/kernel"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.0.0-20260725122641-34be6c0bb073"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-fgmr-7w36-9qfq"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-72796"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/siyuan-note/siyuan/commit/34be6c0bb0739d5b8e99ecc0cbfb474abb16230d"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/siyuan-note/siyuan"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/siyuan-before-access-control-bypass-via-static-routes"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-862" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-04T21:02:22Z",
    "nvd_published_at" : null
  }
}