CVE-2026-72800 is a medium-severity (CVSS 5.8) CWE-862 vulnerability in github.com/siyuan-note/siyuan/kernel. O3 Security confirms whether CVE-2026-72800 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
SiYuan: Missing publish-access filter on getAttributeViewKeysByID discloses database column schema, plus two unscoped block-ID enumeration oracles (publish mode)
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-72800.
Real-World Exposure
github.com/siyuan-note/siyuan/kernelReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
CVE: This vulnerability corresponds to CVE-2026-72800.
Summary
POST /api/av/getAttributeViewKeysByID returns a database's full column schema with no publish-access filtering, while its sibling getAttributeViewKeys applies the filter for reader sessions. Two further endpoints, getBlockDefIDsByRefText and getBlockRelevantIDs return workspace-wide block IDs with no publish scoping. All three are CheckAuth-only, so they are reachable by the publish RoleReader token and by the anonymous account when Publish.Auth.Enable is false.
Details
(a) getAttributeViewKeysByID: ungated column-schema disclosure
The entire handler (kernel/api/av.go, router line 548):
ret.Data = model.GetAttributeViewKeysByID(avID, keyIDs...) // no publish gate
With an empty keyIDs, GetAttributeViewKeysByID calls av.ParseAttributeView(avID) and returns every column's *av.Key:
| Field | Discloses |
|---|---|
Name, Desc | column title and user-authored description |
Options | the full single/multi-select vocabulary and colours (e.g. status labels such as "Fired", "Confidential") |
Template | the column's Sprig template expression — logic and field references |
Relation | the target avID, allowing pivot to another database |
Rollup, NumberFormat, date config | further schema |
Guarded-sibling asymmetry, same file: getAttributeViewKeys (router line 526) runs FilterBlockAttributeViewKeysByPublishAccess(...) when IsReadOnlyRoleContext. getAttributeViewKeysByID applies nothing. A reader who knows an avID — trivially harvested from the data-av-id attribute of any published document embedding a database obtains the schema of any database in the workspace, including those whose host documents are hidden, password-protected, or publish-forbidden. Relation targets allow walking to sibling databases.
(b) Two unscoped block-ID enumeration oracles
Both CheckAuth-only with no publish gate. Neither returns content of its own, but both yield valid block IDs that other endpoints turn into content:
getBlockDefIDsByRefText(router line 237) →GetBlockDefIDsByRefText(anchor)returns the block IDs, workspace-wide and including private documents, whose reference/anchor text equals a caller-supplied string: a ref-text → ID oracle.getBlockRelevantIDs(router line 274) →GetBlockRelevantIDsInBox(id, <notebook from request>)returns parent/previous/next block IDs and traverses decrypted encrypted-notebook structure while the notebook is unlocked, a tree-walk oracle.
Verified at origin/master (eef105683): all three handler bodies contain no publish-access, publish-ignore, or readonly-role check; all three routes are registered CheckAuth without CheckAdminRole.
Proof of Concept
Precondition: publish mode enabled (default port 6808); anonymous when Publish.Auth.Enable is false, otherwise any publish reader account. A database exists whose host document is publish-forbidden or password-protected.
(a) Column schema of any database:
POST http://127.0.0.1:6808/api/av/getAttributeViewKeysByID
{"avID":"<AV_ID>"}
Returns every column's key object names, descriptions, select vocabularies, template expressions, and Relation target avIDs for a database whose host document the reader may not access.
Control: the sibling getAttributeViewKeys with the same avID returns filtered results for the same reader session, confirming the boundary is enforced there and omitted here.
(b) ID oracles:
POST http://127.0.0.1:6808/api/block/getBlockDefIDsByRefText
{"anchor":"<known ref text>"}
→ block IDs workspace-wide, including blocks in private documents
POST http://127.0.0.1:6808/api/block/getBlockRelevantIDs
{"id":"<BLOCK_ID>","notebook":"<BOX_ID>"}
→ parent/previous/next block IDs; traverses encrypted-notebook structure when unlocked
Impact
An anonymous reader (publish mode with auth disabled) or any publish RoleReader can read the complete column schema of any database in the workspace, including column descriptions, select-option vocabularies (which frequently encode sensitive category labels), template logic, and relation targets that permit pivoting to further databases regardless of whether the host document is hidden, password-protected, or excluded from publishing.
The two enumeration endpoints additionally supply valid block IDs across the publish boundary, including from encrypted notebooks while unlocked. This removes the "attacker must already know a valid ID" precondition from other block-read endpoints, converting ID knowledge into content disclosure. Confidentiality-only.
Note
getAttributeViewKeysByID is a distinct handler from getAttributeView; although column definitions also appear within the latter's response payload, a fix applied to one handler does not remediate the other, and getAttributeViewKeysByID has its own filtered sibling (getAttributeViewKeys) demonstrating the intended treatment.
Suggested fix
- Gate
getAttributeViewKeysByIDwithFilterBlockAttributeViewKeysByPublishAccess, mirroringgetAttributeViewKeys. - Scope
getBlockDefIDsByRefTextandgetBlockRelevantIDsto publish-accessible blocks for reader sessions, and ensure the*InBoxtraversal path applies the same check before walking encrypted-notebook structure.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/siyuan-note/siyuan/kernel | all versions | 0.0.0-20260724103335-f36331956ae9 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/siyuan-note/siyuan/kernel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/siyuan-note/siyuan/kernel to 0.0.0-20260724103335-f36331956ae9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-72800 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-72800 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-72800. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-72800 in your dependencies?
O3 detects CVE-2026-72800 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.