CVE-2026-72808 is a medium-severity (CVSS 5.8) CWE-862 vulnerability in github.com/siyuan-note/siyuan/kernel. A fix is available for github.com/siyuan-note/siyuan/kernel — see the affected versions and patch details below.
SiYuan: Missing publish-access filter on getFileAnnotation discloses private PDF annotations of forbidden/protected documents (publish mode)
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-72808.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-72808 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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-2026-72808.
Summary
The /api/asset/getFileAnnotation endpoint returns the content of .sya PDF-annotation files with no publish-access check. It is gated by CheckAuth only, so it is reachable by the publish RoleReader token and by the anonymous account when Publish.Auth.Enable is false. Its sibling, the /assets/* asset route does enforce publish access, including the publish password. An anonymous reader who knows an asset path can therefore read the private PDF annotations (highlights, notes) attached to assets in publish-forbidden, password-protected, or unpublished documents.
Details
getFileAnnotation resolves the annotation file via GetAssetAbsPathInBox (no path traversal) and returns the .sya content. Unlike the /assets/* route, which applies the publish-access filter including password enforcement before serving asset bytes, getFileAnnotation applies no publish-access, publish-ignore, or password check. The guarded-sibling asymmetry indicates the boundary is meant to apply to this data and was omitted here.
.sya files for encrypted-box assets are fail-closed and not exposed. The gap is limited to non-encrypted assets.
Route / auth tier. getFileAnnotation is registered CheckAuth-only. CheckAuth admits RoleReader; the publish proxy forwards port-6808 traffic with a Reader JWT (anonymous when publish auth is disabled).
Proof of Concept
Reproduced on a local instance (publish mode on 6808, Basic Auth off).
Setup (admin, 6806):
createNotebook{name:"AnnotPoc"}→ boxcreateDocWithMd{notebook, path:"/annot-victim", markdown:"doc with a pdf"}→ docPOST /api/asset/upload(multipartid=<doc>,file[][email protected]) →assets/secret-...pdfsetFileAnnotation{path:"<asset>.sya", data:"{annotSecret:ANNOT_SECRET_4471,note:private highlight}"}setPublishAccess{id:<doc>, visible:false, password:"", disable:true}→ doc forbidden
Exploit (anonymous reader, 6808, no token):
POST http://127.0.0.1:6808/api/asset/getFileAnnotation
{"path":"assets/secret-...pdf.sya"}
Returns:
{"code":0,"data":{"data":"{\"annotSecret\":\"ANNOT_SECRET_4471\",\"note\":\"private highlight\"}"}}
The annotation content of a publish-forbidden document is returned to an anonymous reader with no publish-access check, while the /assets/* route serving the same asset class enforces publish access and password.
Impact
An anonymous reader (publish mode with auth disabled) or any publish RoleReader can read the private PDF annotations (highlights and notes) of assets belonging to publish-forbidden, password-protected, or unpublished documents, given the asset path. This defeats the publish-access/password boundary for annotation data. Scope is limited to annotated PDFs in non-encrypted notebooks; encrypted-box annotations are not exposed. Confidentiality-only.
Suggested fix
Apply the same publish-access check the /assets/* route uses to getFileAnnotation resolve the asset's owning document and enforce the publish-access/publish-ignore / password check before returning .sya content.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/siyuan-note/siyuan/kernel | all versions | 0.0.0-20260723031702-509b35055940go get github.com/siyuan-note/siyuan/kernel@v0.0.0-20260723031702-509b35055940 |
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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/siyuan-note/siyuan/kernel to 0.0.0-20260723031702-509b35055940 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-72808 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-72808 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-72808. 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-2026-72808 in your dependencies?
O3 Security finds CVE-2026-72808 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.