SiYuan before v3.7.4 Information Disclosure via getAttributeViewBacklinks

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 versions before v3.7.4 contain an information disclosure vulnerability in the getAttributeViewBacklinks endpoint that consults the forbidden access list instead of the visibility list when filtering backlinks. Anonymous readers can supply a publicly visible database row identifier to discover hidden-tier documents that reference it, receiving the database name, row title, and document path of hidden documents.

Source published

14 Aug 2026 11:35:45 UTC

Source modified

18 Aug 2026 02:03:21 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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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 versions before v3.7.4 contain an information disclosure vulnerability in the getAttributeViewBacklinks endpoint that consults the forbidden access list instead of the visibility list when filtering backlinks. Anonymous readers can supply a publicly visible database row identifier to discover hidden-tier documents that reference it, receiving the database name, row title, and document path of hidden documents.

Source published

Aug 14, 2026, 11:35:45 AM (timezone not stated)

Source modified

Aug 18, 2026, 2:03:21 AM (timezone not stated)

Observed here

7 Nov 2026 15:31:36 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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

EUVD 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

SiYuan versions before v3.7.4 contain an information disclosure vulnerability in the getAttributeViewBacklinks endpoint that consults the forbidden access list instead of the visibility list when filtering backlinks. Anonymous readers can supply a publicly visible database row identifier to discover hidden-tier documents that reference it, receiving the database name, row title, and document path of hidden documents.

Source published

14 Aug 2026 12:16:47 UTC

Source modified

26 Aug 2026 17:04:11 UTC

Observed here

25 Oct 2026 15:19:03 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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

## Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-p4qw-vx5p-g984. This link is maintained to preserve external references. ## Original Description SiYuan versions before v3.7.4 contain an information disclosure vulnerability in the getAttributeViewBacklinks endpoint that consults the forbidden access list instead of the visibility list when filtering backlinks. Anonymous readers can supply a publicly visible database row identifier to discover hidden-tier documents that reference it, receiving the database name, row title, and document path of hidden documents.

Source published

14 Aug 2026 12:31:28 UTC

Source modified

23 Oct 2026 18:45:08 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

CVSS_V4 · 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

Publisher rating · MODERATE

### Summary `/api/av/getAttributeViewBacklinks` filters its results for reader roles through `FilterAttributeViewBacklinksByPublishAccess`. That function resolves its ignore list with `GetDisablePublishAccess`, which covers only the forbidden tier. Documents at the hidden tier are absent from that list, so they pass the check. The result is that an anonymous reader supplying a publicly visible database row receives the database name, row title and document path of rows in hidden documents that reference it. The rest of the function is correct. It takes `*gin.Context` and calls `GetPathPasswordByPublishAccess` and `CheckPublishAuthCookie` at all four decision points, so the password-protected and private tiers are properly enforced. The defect is the choice of list, on one line. ### Details **Route,** `kernel/api/router.go:545` on the development branch and `:527` on master: ```go ginServer.Handle("POST", "/api/av/getAttributeViewBacklinks", model.CheckAuth, getAttributeViewBacklinks) ``` `CheckAuth` only. No `CheckAdminRole`, no `CheckReadonly`. **The defect.** In `FilterAttributeViewBacklinksByPublishAccess` (`kernel/model/publish_access.go:1060` on dev, `:435` on master): ```go publishIgnore := GetDisablePublishAccess(publishAccess) ``` `GetDisablePublishAccess` returns only entries at the forbidden tier. A hidden document has `visible:false`, `password:""`, `disable:false`, so it does not appear in that list. `CheckPathAccessableByPublishIgnore` therefore returns true for it, and because the password is empty the authentication branch short-circuits. Hidden documents pass both halves of the check. **The sibling filter uses the correct list.** The regular backlink panel is the same product feature in the same UI, and it is gated properly. `kernel/api/ref.go:170` `getBacklink2` calls `FilterPathsByPublishAccess`, which at `kernel/model/publish_access.go:1256` resolves its list with `GetInvisiblePublishAccess`. Two backlink filters in the same file, opposite list choices. **The distinction the tiers are meant to draw.** The shipped description of the hidden tier, from `app/appearance/langs/en.json`: ``` publishAccessHiddenComment = "Not publicly visible, can be accessed directly." ``` A direct-access endpoint using the forbidden list is consistent with that: hidden documents are meant to be reachable when the caller already knows the identifier. Backlink discovery is not direct access. The caller supplies the target row and receives the identities of referring rows it never named, which is enumeration, and enumeration is precisely what "not publicly visible" excludes. **Origin.** The filter was introduced by `6da2c736e` (2026-07-18, "Show database relation backlinks in the attribute panel", #10599) with this list choice from the start. No security-focused commit has touched the attribute-view backlink path since. **What is returned.** Per matched backlink: `AvName` (the database name), `Title` (the row title), `DatabasePath` (the HPath of the containing document), `BoxID`, `DatabaseBlockID`, and `Relations[].KeyName`. These are author-written names and titles, not opaque identifiers. ### Proof of Concept Publish mode enabled, `Publish.Auth.Enable` false, anonymous client with no credentials or cookies. Document A is public and holds a database with a row. Document B is set to varying tiers and holds a database whose relation field points at A's row. The attacker needs only A's `avID` and `itemID`, both present in the DOM of A's own published page. Listing control first, establishing that the platform agrees B must not be listed: ``` POST /api/filetree/listDocsByPath → returns only the public document ``` Then the same backlinks request at four tier settings, spaced to clear the 30-second `GetPublishAccess()` cache: | Tier of document B | Result | |---|---| | Hidden (`visible:false`, no password, `disable:false`) | `total:1`, with `avName`, `title`, `databasePath` and `relations[].keyName` for the row in B | | Forbidden (`disable:true`) | `total:0` | | Private (password set) | `total:0` | | Hidden again (restored) | `total:1`, reproducible | The forbidden row confirms that the disable list is what the filter consults. The private row confirms that the password half works correctly. The gap is the hidden tier alone. ``` POST /api/av/getAttributeViewBacklinks {"avID":"<public database id>","itemID":"<public row id>"} → 200, total:1, disclosing the database name, row title and document path of a document the same session cannot list ``` ### Impact An anonymous reader in publish mode, or any publish `RoleReader`, discovers that a hidden document contains a database row referencing a public one, and receives that row's title, its database's name, and the containing document's path. Names and titles are author-written and routinely describe their subject, so this discloses both the existence and the topic of documents the author marked as not publicly visible. The reader does not need to know anything about the hidden document beforehand. The only input is a public row identifier taken from a page they are already entitled to view. Confidentiality only, with no integrity or availability impact. No document body content is returned. ### Suggested fix Change the list resolution in `FilterAttributeViewBacklinksByPublishAccess` to `GetInvisiblePublishAccess`, mirroring `FilterPathsByPublishAccess` on the regular backlink path. The password handling in the function is already correct and needs no change.

Source published

23 Oct 2026 18:30:42 UTC

Source modified

5 Nov 2026 23:26:06 UTC

Observed here

5 Nov 2026 23:38:32 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: The publish filter for database backlinks consults the forbidden list instead of the visibility list, disclosing hidden-tier documents to anonymous readers in github.com/siyuan-note/siyuan/kernel

Source published

5 Nov 2026 22:54:22 UTC

Source modified

5 Nov 2026 23:15:13 UTC

Observed here

5 Nov 2026 23:38:32 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.