SiYuan before v3.7.4 Access Control Bypass via Static Routes

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

SiYuan before v3.7.4 contains an access control bypass vulnerability where static-file routes in the server mux bypass publish-access controls enforced on the REST API. Attackers with publish reader tokens or anonymous access in disabled-auth mode can read templates, snippets, and export artifacts by directly accessing static routes that lack the same restrictions as their REST API counterparts.

Source published

12 Aug 2026 19:07:43 UTC

Source modified

14 Aug 2026 16:52:04 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N

CVSS 3.1 · 5.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

SiYuan before v3.7.4 contains an access control bypass vulnerability where static-file routes in the server mux bypass publish-access controls enforced on the REST API. Attackers with publish reader tokens or anonymous access in disabled-auth mode can read templates, snippets, and export artifacts by directly accessing static routes that lack the same restrictions as their REST API counterparts.

Source published

12 Aug 2026 20:17:51 UTC

Source modified

24 Oct 2026 15:10:00 UTC

Observed here

25 Oct 2026 15:19:03 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · [email protected] · Secondary · 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS 3.1 · [email protected] · Primary · 5.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

**CVE:** This vulnerability corresponds to [CVE-2026-72796](https://nvd.nist.gov/vuln/detail/CVE-2026-72796). ### Summary Several 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`. Most notably, `/templates/` serves `data/templates` a directory the REST file API explicitly refuses to serve to non-administrators. ### Details | Route | Registration | Guard | Exposed to a reader | |---|---|---|---| | `/templates/*` (line 424) | `Group("/templates/", model.CheckAuth).Static("", data/templates)` | none beyond path cleaning | the templates directory | | `/snippets/*` (line 434) | `CheckAuth` | blocks only `conf.json` | any snippet's JS/CSS content by name | | `/widgets/`, `/plugins/`, `/emojis/` (409/414/419) | `Group(CheckAuth).Static(dir)` | none | whole directory trees | | `/export/*` (line 320) | `Group("/export/", CheckAuth)` | traversal, sensitive-path and DEK guards: **no publish check** | export artifacts (PDF/HTML/DOCX/CSV) | **`/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. **`/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. **Confirmed correctly gated, for contrast:** `/assets/*` (publish-gated), `/history/*` and `/repo/diff/*` (`CheckAdminRole`), `/debug/pprof/*` (disabled in production builds), `/public/` (intentionally public). All four routes above were verified to carry `CheckAuth` only, no `CheckReadonly`, no `CheckAdminRole`. ### Proof of Concept Precondition: publish mode enabled (default port 6808), anonymous when `Publish.Auth.Enable` is `false`, otherwise any publish reader account. **Templates: served despite the REST API refusing them:** ``` GET http://127.0.0.1:6808/templates/<template-file>.md → 200, template content ``` The equivalent REST request is refused: ``` POST http://127.0.0.1:6808/api/file/getFile {"path":"data/templates/<template-file>.md"} → 403 (refuseToAccess) ``` The same reader session obtains the file through the static route. **Snippets:** ``` GET http://127.0.0.1:6808/snippets/<snippet-name>.js → 200, snippet source ``` **Export artifacts (conditional on a predictable name while the artifact exists):** ``` GET http://127.0.0.1:6808/export/csv/<doc-name>/<doc-name>.csv → 200, exported content of a document the reader has no publish access to ``` ### Impact An 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. ### Suggested fix Apply 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.

Source published

4 Sep 2026 21:02:22 UTC

Source modified

10 Sep 2026 15:25:50 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

Publisher rating · MODERATE

SiYuan: Static-file routes bypass the publish-access controls enforced on the REST API, exposing templates, snippets and export artifacts to anonymous readers in github.com/siyuan-note/siyuan/kernel

Source published

10 Sep 2026 14:48:42 UTC

Source modified

10 Sep 2026 15:15:15 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.