CVE-2026-72800 in SiYuan
Summary
by MITRE • 08/12/2026
SiYuan versions before v3.7.4 fail to apply publish-access filtering to the getAttributeViewKeysByID endpoint, allowing authenticated readers to retrieve complete database column schemas including descriptions, select vocabularies, and template expressions. Additionally, getBlockDefIDsByRefText and getBlockRelevantIDs endpoints enumerate workspace-wide block IDs without publish scoping, enabling attackers to discover valid block identifiers across publish boundaries and access content from hidden or password-protected documents.
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Analysis
by VulDB Data Team • 08/12/2026
The vulnerability in SiYuan versions prior to v3.7.4 represents a critical authorization bypass flaw that undermines the application's data access controls and information disclosure protections. This weakness manifests through multiple endpoints that fail to properly enforce publish-access filtering mechanisms, creating pathways for authenticated users with read-only privileges to access sensitive database metadata and content structures that should remain restricted. The vulnerability specifically targets the getAttributeViewKeysByID endpoint where the system neglects to apply necessary access controls, allowing unauthorized information retrieval from database schemas that contain descriptions, select vocabularies, and template expressions typically reserved for privileged users.
The technical flaw stems from inadequate input validation and access control enforcement within the SiYuan application's API layer. The system fails to properly scope queries to the user's current publish context when processing requests through getAttributeViewKeysByID, getBlockDefIDsByRefText, and getBlockRelevantIDs endpoints. This oversight creates a direct information disclosure channel where attackers can enumerate workspace-wide block identifiers without proper authorization checks. The absence of publish scoping in these operations enables malicious actors to discover valid block identifiers across different publish boundaries, effectively bypassing the intended document access controls that should restrict visibility to only those documents accessible through specific publish permissions.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially enable more sophisticated attacks within the SiYuan environment. Attackers can leverage the exposed database column schemas to understand the underlying data structures and potentially identify additional attack vectors or system weaknesses. The enumeration capabilities provided by the unfiltered block ID endpoints create opportunities for targeted attacks against specific documents, as adversaries can discover valid identifiers for password-protected or hidden content without requiring knowledge of the actual document names or locations. This information exposure significantly weakens the overall security posture by reducing the attacker's reconnaissance time and increasing their ability to craft targeted exploitation attempts.
Organizations using SiYuan versions before v3.7.4 face substantial risks from this vulnerability, particularly in environments where multiple users with varying access levels collaborate on shared workspaces. The exposure of internal database schemas provides attackers with detailed insights into the application's architecture and data organization patterns, potentially enabling more effective exploitation of other vulnerabilities or targeted attacks against specific document collections. The vulnerability aligns with CWE-284 (Improper Access Control) and represents a clear violation of the principle of least privilege, as authenticated users can access information beyond their designated permissions. From an attacker's perspective, this vulnerability maps to several ATT&CK techniques including T1087 (Account Discovery), T1566 (Phishing), and T1593 (Search Open Technical Databases) by providing unauthorized access to internal system information that can be used for further compromise.
The recommended mitigations include immediate upgrade to SiYuan version 3.7.4 or later, which implements proper publish-access filtering across all affected endpoints. Organizations should also implement additional monitoring controls to detect unusual patterns of block ID enumeration and attribute schema requests from authenticated users. Security teams should review existing access control policies and ensure that publish scoping is consistently applied across all API endpoints that handle workspace-wide data queries. Network segmentation and API rate limiting can provide additional defense-in-depth measures while the primary fix is being implemented. Regular security assessments should be conducted to verify that similar access control weaknesses do not exist in other application components, particularly around metadata exposure and information disclosure vulnerabilities.