CVE-2026-86192 Overview
CVE-2026-86192 is an information disclosure vulnerability in SiYuan, an open-source personal knowledge management application. Versions before v3.8.2 fail to properly filter private attribute-view cell values in the getAttributeViewKeys endpoint. Publish readers can retrieve hidden KeyValues payloads from rows bound to inaccessible documents. The flaw exposes private database contents without authorization and maps to CWE-639: Authorization Bypass Through User-Controlled Key.
Critical Impact
Authenticated publish readers can exfiltrate confidential attribute-view data belonging to documents they should not be able to access, breaking the platform's document-level access controls.
Affected Products
- SiYuan note-taking application versions prior to v3.8.2
- Deployments exposing the publish reader role to untrusted users
- Self-hosted SiYuan instances that share attribute views across documents
Discovery Timeline
- 2026-09-05 - CVE-2026-86192 published to NVD
- 2026-09-10 - Last updated in NVD database
Technical Details for CVE-2026-86192
Vulnerability Analysis
SiYuan supports attribute views, a database-like feature that stores structured KeyValues payloads associated with document rows. The getAttributeViewKeys endpoint returns these payloads to authenticated users. Prior to v3.8.2, the endpoint does not verify whether the caller has access to the underlying document bound to each row. As a result, a user holding only the publish reader role can request attribute-view keys and receive cell values from rows tied to documents that are otherwise inaccessible to them. The disclosed content may include private notes, credentials pasted into cells, project metadata, or any other data stored inside attribute views.
Root Cause
The root cause is missing authorization enforcement on a per-row basis inside the getAttributeViewKeys handler. The endpoint authenticates the caller but does not re-check document-level permissions when assembling the response. This is a classic Insecure Direct Object Reference pattern classified under CWE-639, where an authenticated identity can address objects belonging to other principals by supplying the corresponding view or key identifier.
Attack Vector
Exploitation requires network access and a low-privilege account, typically the publish reader role that SiYuan exposes on published notebooks. The attacker sends a crafted request to the getAttributeViewKeys endpoint referencing an attribute view whose rows point to protected documents. The server returns the hidden KeyValues payloads without performing the missing authorization check. No user interaction is required and the flaw does not affect integrity or availability, only confidentiality. Full technical details are documented in the GitHub Security Advisory GHSA-vc7j-5f5p-3x75 and the VulnCheck Advisory on Siyuan.
Detection Methods for CVE-2026-86192
Indicators of Compromise
- Repeated requests to the getAttributeViewKeys endpoint originating from publish reader accounts.
- Response payloads containing KeyValues entries referencing document identifiers the requesting user has not opened via the standard UI.
- Unusual volume of attribute-view enumeration from a single session or IP address.
Detection Strategies
- Review SiYuan application logs for getAttributeViewKeys calls correlated against the caller's document permission set.
- Instrument the reverse proxy in front of SiYuan to capture request paths and JSON response sizes for anomaly analysis.
- Compare returned attribute-view row counts to the number of documents the requesting principal is authorized to view.
Monitoring Recommendations
- Forward SiYuan access logs to a centralized SIEM or data lake with retention sufficient to reconstruct exfiltration attempts.
- Alert on publish reader sessions that issue high volumes of API calls to attribute-view endpoints.
- Track version metadata across SiYuan instances to identify hosts still running versions earlier than v3.8.2.
How to Mitigate CVE-2026-86192
Immediate Actions Required
- Upgrade all SiYuan instances to v3.8.2 or later, which restores the missing authorization checks.
- Audit publish reader accounts and revoke access for users who no longer require published notebook consumption.
- Rotate any credentials or secrets that were stored inside attribute-view cells on affected instances.
Patch Information
The vendor addressed the vulnerability in SiYuan v3.8.2 by filtering private attribute-view cell values in the getAttributeViewKeys endpoint. Patch and release notes are referenced in the GitHub Security Advisory GHSA-vc7j-5f5p-3x75.
Workarounds
- Disable the publish feature on notebooks that contain sensitive attribute views until the upgrade is applied.
- Restrict network access to the SiYuan API using firewall or reverse-proxy rules that only allow trusted clients.
- Remove sensitive content from attribute-view cells and store it in access-controlled documents that are not referenced by shared views.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
