Description

SiYuan versions before v3.7.4 fail to validate publish-password tier in getGraph and getLocalGraph endpoints, allowing anonymous readers to retrieve block-level content of password-protected documents. Attackers can call these endpoints without supplying a password to read protected document content and the complete reference topology.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.6",
  "pubDate": "2026-08-12T20:17:52.383Z",
  "pubdate": "2026-08-12T20:17:52.383Z",
  "executiveSummary": "An authentication bypass vulnerability exists in SiYuan versions prior to v3.7.4, specifically within the publish-password tier validation logic for graph retrieval endpoints. The flaw allows unauthenticated remote attackers to bypass access controls and interact directly with sensitive API functions without supplying the required publish password. Consequently, anonymous readers gain unauthorized access to confidential block-level content and comprehensive reference topologies of password-protected documents. This security failure severely compromises document confidentiality and information privacy within affected deployments. The attack requires network connectivity to the targeted SiYuan instance and knowledge of the specific API endpoints, but completely negates any password protection mechanisms configured by document publishers. Organizations utilizing vulnerable versions face immediate risk of unauthorized data exfiltration, topological mapping of private notes, and exposure of proprietary information stored within the knowledge management platform.",
  "technicalDetails": "The vulnerability resides in the core backend logic governing the getGraph and getLocalGraph API endpoints within SiYuan prior to version v3.7.4. The root cause is the absence of proper input validation and enforcement of the publish-password tier during endpoint execution. When a client issues a request to retrieve graph data or local graph hierarchies, the application logic fails to verify whether the requesting session or payload has successfully authenticated against the associated publish password protection layer. As a result, the access control check is bypassed entirely, allowing unauthenticated, anonymous users to invoke these functions successfully. The attack flow begins with an external entity identifying a SiYuan instance exposing the vulnerable API routes over the network. The attacker crafts HTTP requests targeting the getGraph and getLocalGraph endpoints. Due to the missing validation check in the vulnerable component, the backend processes the request and returns the requested data payloads, which include granular block-level document content and complete inter-document reference topologies. No specialized privileges or prior authentication tokens are required to execute this payload behavior. The post-exploitation impact includes the full disclosure of protected document content, structural knowledge graphs, and metadata relationships that were intended to be restricted to authorized users possessing the correct publish password. The vulnerability affects all SiYuan deployments running software versions prior to v3.7.4 where document publishing with password tiers is utilized."
}